After some beta-testing, as well as a week of live raiding and heroics, I believe I've stumbled upon a new way to look at rotations to explain why our secondary resources generate relatively slowly. From all my play testing, I've seen a fundamental shift of focus in the Warlock's rotation. A Mage's rotation is about spamming one little spell until something more interesting pops up. A Balance Druid can shift between Eclipses in less than 15 seconds. But not Warlocks. Our class no longer is narrowly concerned with what spell to cast after the other. No, the length of our rotations are so long, they encompass entire boss fights. What Warlocks are receiving in Pandaria isn't a new rotation; it's an entirely new take on the rotation model.
What we have is a Meta-rotation. Just like we have the Meta-game—all the theory crafting, the databases, the guilds, etc, that makes the game more than finishing quests and downing bosses—Warlocks have a rotation that encompasses more than simply pushing buttons in the right order. The time between generating resources and spending them is so long that the Meta-rotation encompasses whole portions of fights, instead of seconds of it. In Heroics, I've found that the Meta-rotation can even encompass all the mobs between bosses, where I have to consider how to spend my secondary resources per pull, instead of per enemy.
That unfulfilled promise of utility that Soul Shards gave during Cataclysm can finally be realized. Because Soul Shards were fixed and permanent throughout the fight, spells that had a Soul Burn effect had to be balanced around being powerful enough to use throughout a long fight, while at the same time being not quite powerful enough to trivialize short fights. Obviously this just couldn't be done, so this long term, damage or utility resource system evolved into an entire rotation above the normal rotation. The current Meta-rotation allows generation of resources inside combat, but also scales that generation to require so much input, so much time, that the spells using the secondary resources can actually be of substantial power, make a real difference, at the same time not being overpowered. The Meta-rotation can accommodate any length fight, because it is based on actually generating secondary resources, as opposed to spending a preset number. The Meta-rotation still maintains though the advantage of having the player specifically decides when and where those powerful damage or utility spells are needed.
The other major outcome of this is that Warlocks now possess a rather unique form of burst. All three specs have a way to essentially kick their damage into high gear for a sustainable amount of time without the need for cooldowns by building up a secondary resource that can be used for higher damage later. In every case, the Warlock decides how and when that extra damage is used. In Patchwerk-style fights, you can simply spread out the damage evenly throughout the encounter, but if there are certain critical phases of a fight, such as a burn phase, or an AoE phase, those damage boosts can be saved up and unleashed. A Warlock's damage throughout any boss will have rather huge peaks and valleys, but they will add to respectable overall DPS.
Each spec, of course, has very different takes on this basic premise, but I've seen this concept imbedded in all three specs. Each one takes the concept into different directions and applies them differently, but the effect is always the same. Your rotation is designed to change based on the conditions of the fight, and shifts over a long period of time, rather than shifting in the short term.
Destruction
Destruction's Meta-rotation is the simplest of all three of the new specs. It's based on a very simple input/output system. By casting Incinerate, the Destruction Warlock builds up Burning Embers, which then can be cast for powerful Chaos Bolts. The ratio is around ten Incinerates for one Chaos Bolt, but can be lower because an Incinerate that crits generates double the amount of Burning Embers. These can be saved with no penalty, giving the Destruction Meta-rotation a commutative property. That means that no matter what the order of Burning Ember generation and spending, the overall DPS at the end of an encounter will always be the same.
For example, let's suppose you have a boss fight of one and a half minutes in length. Not accounting for haste and crit, you'll be able to cast forty Incinerates, generating four Burning Embers, and spend those Burning Embers on five Chaos Bolts, including a Burning Ember that you start the fight with. So, suppose you cast ten Incinerates, generating one Burning Ember. At this point, you can cast a Chaos Bolt, and then repeat casting Incinerates, doing this cycle until the fight is over. You can also continue to generate Burning Embers, waiting until you've reached the cap. Then, you'll have three Burning Embers to spend any way you wish. You can spend them all in a row or you can just spend one, and sit on the other two for later. But, no matter what you do, your overall DPS will always remain the same. The number of Burning Embers usable is constant, no matter what order they are consumed in. This is the essence of Destruction's Meta-rotation.
What all this means is that the major consideration in spending Burning Embers isn't getting the most out as quickly as possible. The Meta-rotation is far too long term for that kind of thinking. Instead, a Destruction Warlock considers which parts of the fight needs the Burning Embers. Take Warlord Zon'ozz. The basic strategy in the normal Dragon Soul is to bounce the void orb until you unleash it on Zon'ozz, giving him a debuff where he takes more damage. This small burn window is when the DPS really matters. So a Destruction Warlock may generate all the Burning Embers possible, and sit on them until this burn phase begins, unleashing all three Chaos Bolts at once. Then, once the burn phase is over, and the void orb is bouncing again, that Warlock returns to a low Burning Ember consumption rotation, building up as many Burning Embers as needed, spending only one Burning Ember when the cap is reached, until the burn phase comes up again. This on-demand damage can also be used for AoE, using an ability called Fire and Brimstone. Using it consumes an Ember, just as Chaos Bolt does, but makes the next Incinerate, Immolate, or Conflagration hit all targets in an area. This lets a Destruction Warlock not just have huge burst potential with Chaos Bolts, but AoE burst by shooting out Incinerates and Immolates everywhere.
"Flames! More flames!"
The key to using these burst abilities, though, is knowing when the fight requires Burning Ember use, and changing the rotation around these requirements.
Demonology
The basic premise of Demonology's Meta-rotation is very similar to Destruction's. The Demonologist Warlock builds up a secondary resource, Demonic Fury, by casting the entire repertoire of spells: Corruption, Shadow Bolt, Hand of Gul'dan. Instead of spending Demonic Fury on a specific high damage ability, like Destruction, Demonology spends Demonic Fury on time in Metamorphosis. Metamorphosis grants the Warlock not just increase damage and better AoE, but it allows all those things with far more flexibility. The biggest flexibility is mobility, that almost every spell available in Metamorphosis is an instant cast.
The exchange for this rather powerful boost for multiple situations is that the Demonologist is building up Demonic Fury for time spent in Metamorphosis, as opposed to a direct spike of damage. That makes the Meta-rotation more active, where using Metamorphosis requires not just the right opportunity, but the right amount of time to get the full use of Metamorphosis. Moreover, because Metamorphosis can be manually deactivated, a Demonologist can change the momentum of spending Demonic Fury, stopping at any point in Metamorphosis to save the resource for later. Time itself is the prime consideration with Metamorphosis. It's not a matter of being in Metamorphosis or not, it's also a matter of how much time you're willing to spend in Metamorphosis.
Armies of Imps. What else could a Warlock desire?
On your standard Patchwerk, tank-and-spank fight, Demonology's optimal Meta-rotation is to simply build up Demonic Fury to max, then spend all of it in one sitting of Metamorphosis. This is actually an advantage for Demonology, that it has a simple base Meta-rotation, while the others are based on the idea that the Warlock is choosing where to put the damage increasing spells, even if it is a Patchwerk-style fight. But in fights where there are burn phases or AoE phases, the momentum of Demonic Fury generation has to be cut short for the immediate benefit, but at the expense of less time using the benefit. For example, on Warlord Zon'ozz, you may reach full Demonic Fury before he finishes his void sphere phase. To keep all the Demonic Fury for the burn phase, the Demonologist will spend only some time in Metamorphosis, depleting whatever amount of Demonic Fury that can be built up before the burn phase begins. You have to stop the momentum from Metamorphosis, to allow for that Demonic Fury to be used later. The converse is also true though. During the Yor'sahj fight, a Demonologist may have only built up half the maximum Demonic Fury when a black glob is summoned. That Warlock will only have half the time in Metamorphosis, but will have all the same damage increasing abilities.
While Destruction and Affliction have very specific abilities to cast at specific instances, the key to Demonology's Meta-rotation is time. Knowing not just when in the sequence of a fight Metamorphosis is required, but for how long. The key to using Metamorphosis is the ability to shift between it expertly throughout a whole encounter.
Affliction
Affliction's Meta-rotation is perhaps the most complicated to explain, as it deviates substantially from the former two specs. Firstly, it is generated randomly instead of directly. Secondly, the secondary resource gained, Soul Shards, is actually much closer to a conventional resource than Demonic Fury or Burning Embers. It's easy the most short term of the three Meta-rotations. The goal for an Affliction Warlock is to attempt to keep Haunt—now a boosting spell that increases damage taken and costs a Soul Shard—up at the best times, either spread out throughout a fight or concentrated on certain crucial phases. If that phase calls for multi-DoTing or massive AoE, Soul Burn can be used on either Soul Swap, for the former, and Seed of Corruption, for the latter.
"So much suffering, trapped in one little shard."
The best metaphor I can offer for just how to manage Affliction's Meta-rotation is that it is like a budget game. An Affliction Warlock essentially has a 25% chance to generate a Soul Shard every time Corruption deals damage, but starts with the maximum Soul Shards possible at the beginning of a fight. So, on the one hand, Affliction Warlocks can't spend more shards than they take in, otherwise they will be starved of their secondary resource, and reliant on that 25% chance to use their abilities. But, at the same time, if Affliction Warlocks only cast a Haunt, or use Soul Burn, when a Soul Shard is generated, their DPS will be subject to the random number generator. Thus, the Affliction Meta-rotation is designed to juggle their resources, spending just as much as can be replenished while spreading out the usage to do the maximum DPS as possible. So, when a boss has a burning phase, an AoE phase, or a situation where multi-DoTing is needed, Affliction can spend into the saved Soul Shards.
An Affliction Warlock has to actively spend Soul Shards throughout any fight, to make sure there's an empty space for a Soul Shard that may generated. So, in your standard Patchwerk-style fight, an Affliction Warlock can actually cheat the random number generator a little to keep Haunt up consistently throughout the fight. Suppose it's been far too long since a Soul Shard has been generated. A clever Warlock can simply deficit spend a Soul Shard, knowing that one will be generated later. On fights with a burn phase or some other critical phase, those saved shards are going to be necessary to use immediately at the critical point. On a fight like Warlord Zon'ozz, an Affliction Warlock need only chain Haunts, keeping the debuff on the Warlord for as long as there are surplus Soul Shards to burn, and then saving any Soul Shards generated afterwards for the next burn phase. On an AoE fight, such as Yor'sahj, Soul Burn can be used combined with Seed of Corruption, which will leave a single Corruption DoT on all targets hit by the explosion, but Haunt can also be kept up on the main boss to keep doing damage. The same principle is also true for Multi-DoTing, using Soul Burn with Soul Swap to put all three DoTs on the other target.
The core of Affliction's Meta-rotation is this kind of income, saving, and spending system. Maximizing DPS comes from balancing all three during a fight, so that you're always generating more Soul Shards, throttling damage up, while saving just enough for those key phases. Affliction seems to be built around this constant budgeting of Shards, and while big critical moments in a fight are key parts of playing the other two specs, it's just another variable in the soul budget for the Affliction Warlock.
"I don't care which Warlock is on your resume, you're working for me now!"
So, welcome to the Meta-rotation, and the new Warlock class. I personally think there's been an identity crisis for Warlocks for a long time. For so long the class was defined by having pets, or having DoTs or debuffs, or having a giant toolbox of spells, but these a class does not make. For far too long, Warlocks and Mages were pretty much synonymous, nothing but a thematic difference. But, finally there's a niche that no other class has ever delved into. Having a rotation that spans such a long breadth of time, that every aspect of a fight had to be considered, is a quality that is rather unique, and, I feel, fresh. I predict that long-term planning will become a central part of the class, and players who can manage a little long-term planning will be drawn to Warlock. The new Warlock will reward players who can plan far ahead, who can see a whole fight, instead of just small phases. It will not be about a simple rotation of this spell, that spell, other spell, and cooldown when needed. Our spells will be of a far grander scope, their reach spanning across entire encounters, with power befitting the amount of effort put into keeping that kind of perspective. A Warlock with just enough wit will be able to unleash a torrent of demonic powers, hellfire, or withering darkness just when a raid is pushed to its limits. This kind of Meta-rotation will mark Warlocks as being the devious, conniving, plotting masterminds of Azeroth, always three steps ahead of any opponent. And I love it.