WoW: An Argument for Warlock Tanks
I've seen a dozen arguments for this so far, but this is mine.
A History of Warlock Tanking
Firstly, this is not out of the blue. Warlocks have had a history of being far more tanky than other pure DPS classes.
In original WoW, Warlocks were noted for their ability to take down elites above their level due to the drain tanking strategy. Not at all suitable for even 5man tanking, but the seeds of Warlock tanking were already there. I have personally used this to tank Onixia for about 30s when the main tank died, until an off-tank picked her up. Wouldn't have held much longer, but any other pure DPS class at the time would have been splatted quite fast.
In AQ40, there was a specific boss (The Twin Emporers) which required a caster tank - almost always a Warlock. We had the appropriate resist bonuses, significant gains to our health above other caster classes, and abilities with threat gain. As a trade off during the fight, you could switch from searing pain (the threat gain spell) to drain tanking with life-drain, trading threat for survivability.
Finally, in Naxxramas (original) there were cloth gear drops with Stamina gains above that off plate tanking gear. Useless for any other caster, they were quickly given to warlocks, who could use the massive health further tank, and also use as mana via lifetap.
Come Burning Crusade Warlocks gained Metamorphosis. This came with a massive armour boost (and I believe health as well, but can't recall correctly), enough to easily make us a tank. We also gained a honest pure Taunt. Unfortunately Metamorphosis didn't last long enough to seriously tank anything other than the odd questing mob, or brief accidental aggro pull.
Even now, Metamorphosis still makes a Warlock very tanky, but still has it's limited duration so can never be used for serious tanking.
However, the idea of a Warlock tank is not new, and has the seeds since World of Warcraft started.
Why WoW needs a caster tank
Almost all raids require a main tank, and an off-tank. In addition, a raiding group usually needs a back-up tank or two, for those times when one of primary tanks is unable to make it. This unfortunately affects the overall raid make up, and shifts the balance towards raid groups being melee heavy.
The only tank class currently that has a ranged DPS alternate spec is the Druid. All others are melee DPS.
The Paladin and Druid classes can have a tank spec, and a healer spec. But in all honestly, this is an extremely unlikely configuration for a raider. If they are running as a primary tank, their offspec is likely to be DPS they can switch to for those fights than only need one tank.
If a person who normally heals swaps in as the tank when one of the primary tanks are away, the raid has just shifted the problem, because in all honestly, most raid groups have DPS people sitting in their reserves, not healers or tanks.
Hence the highly likely point that your spare tanks are running as Melee DPS instead.
Looking at a likely 10man raid make up:
2 tanks (main and off)
1 melee DPS and spare tank.
2 healers.
Giving us 5 slots for other DPS.
If we assumed an equal potential mix of classes, there are 4 classes pure melee, 4 pure ranged, and two that can do either melee or ranged. So an equal mix.
If this is split equally, for a 2 tank fight, the raid could either be equal in terms of Melee vs Ranged, or 2 Melee above the Ranged, depending on where the last position falls in the split.
For a one tank fight, your raid make-up shifts towards melee further, because of the high likely-hood your tank's alternate spec is DPS.
However, even with the ranged classes they have pets that are usually melee as well.
Adding the Monk into the game, as a potential tank doesn't fix this problem. If anything, it'll make it worse, by increasing the number of melee classes. And shifting the chances further away from the potential of the Druid ranged/tank.
One solution towards adjusting this, is of course make a another tank class that can also do a ranged DPS spec. Without adding any further classes, the closest there already is of course: The Warlock
MoP: The Warlock Glyph and Balance
The currently glyph allows a Demonology Warlock to shift into a tankish form at the click of a button - usable in combat (at least last time I logged into Beta).
While not powerful enough for full tanking, it is still far superior to any-non tanking class at it, and has potential use as a light off-tank, or last-minute raid-saver - both very circumstantial.
The arguments against it being brought up to full tanking have been that the Developers at Blizzard would have to balance this "new" tank class in with the others. Leaving it only as a light tank avoids this.
Or does it?
It avoids the problem only for one part of WoW: PvE.
In PvP it will still need to be balanced against other classes. Given the dramatic changes the glyph does to the class in terms of armour, health, and Demon Form abilities, it will still have to be considered for the effect on PvP balance.
I suspect the solution will unfortunately be just the nerfing of any abilities in the glyph form if they turn out to be an issue in PvP, until the glyph is just an oddity - used only in bizzare circumstances, if the Warlock in question even remembers they have it.
But my point lies, in that it will have to be considered anyway, meaning some of the effort in considering its balance will already be being done.
Secondly, as MoP is still in Beta, and given the Warlock class is undergoing a massive overhaul anyway, it's currently not too late for the potential of the Demonology spec becoming a full tank spec - doing away with the glyph completely.
Anyway, we can but hope.
I love the Warlock, starting mine the day World of Warcraft started. I played him almost exclusively until the Death Knight became available - far closer to my dream of a tanking death caster. I would switch back to my Warlock full time if I could tank with him in raids.
A History of Warlock Tanking
Firstly, this is not out of the blue. Warlocks have had a history of being far more tanky than other pure DPS classes.
In original WoW, Warlocks were noted for their ability to take down elites above their level due to the drain tanking strategy. Not at all suitable for even 5man tanking, but the seeds of Warlock tanking were already there. I have personally used this to tank Onixia for about 30s when the main tank died, until an off-tank picked her up. Wouldn't have held much longer, but any other pure DPS class at the time would have been splatted quite fast.
In AQ40, there was a specific boss (The Twin Emporers) which required a caster tank - almost always a Warlock. We had the appropriate resist bonuses, significant gains to our health above other caster classes, and abilities with threat gain. As a trade off during the fight, you could switch from searing pain (the threat gain spell) to drain tanking with life-drain, trading threat for survivability.
Finally, in Naxxramas (original) there were cloth gear drops with Stamina gains above that off plate tanking gear. Useless for any other caster, they were quickly given to warlocks, who could use the massive health further tank, and also use as mana via lifetap.
Come Burning Crusade Warlocks gained Metamorphosis. This came with a massive armour boost (and I believe health as well, but can't recall correctly), enough to easily make us a tank. We also gained a honest pure Taunt. Unfortunately Metamorphosis didn't last long enough to seriously tank anything other than the odd questing mob, or brief accidental aggro pull.
Even now, Metamorphosis still makes a Warlock very tanky, but still has it's limited duration so can never be used for serious tanking.
However, the idea of a Warlock tank is not new, and has the seeds since World of Warcraft started.
Why WoW needs a caster tank
Almost all raids require a main tank, and an off-tank. In addition, a raiding group usually needs a back-up tank or two, for those times when one of primary tanks is unable to make it. This unfortunately affects the overall raid make up, and shifts the balance towards raid groups being melee heavy.
The only tank class currently that has a ranged DPS alternate spec is the Druid. All others are melee DPS.
The Paladin and Druid classes can have a tank spec, and a healer spec. But in all honestly, this is an extremely unlikely configuration for a raider. If they are running as a primary tank, their offspec is likely to be DPS they can switch to for those fights than only need one tank.
If a person who normally heals swaps in as the tank when one of the primary tanks are away, the raid has just shifted the problem, because in all honestly, most raid groups have DPS people sitting in their reserves, not healers or tanks.
Hence the highly likely point that your spare tanks are running as Melee DPS instead.
Looking at a likely 10man raid make up:
2 tanks (main and off)
1 melee DPS and spare tank.
2 healers.
Giving us 5 slots for other DPS.
If we assumed an equal potential mix of classes, there are 4 classes pure melee, 4 pure ranged, and two that can do either melee or ranged. So an equal mix.
If this is split equally, for a 2 tank fight, the raid could either be equal in terms of Melee vs Ranged, or 2 Melee above the Ranged, depending on where the last position falls in the split.
For a one tank fight, your raid make-up shifts towards melee further, because of the high likely-hood your tank's alternate spec is DPS.
However, even with the ranged classes they have pets that are usually melee as well.
Adding the Monk into the game, as a potential tank doesn't fix this problem. If anything, it'll make it worse, by increasing the number of melee classes. And shifting the chances further away from the potential of the Druid ranged/tank.
One solution towards adjusting this, is of course make a another tank class that can also do a ranged DPS spec. Without adding any further classes, the closest there already is of course: The Warlock
MoP: The Warlock Glyph and Balance
The currently glyph allows a Demonology Warlock to shift into a tankish form at the click of a button - usable in combat (at least last time I logged into Beta).
While not powerful enough for full tanking, it is still far superior to any-non tanking class at it, and has potential use as a light off-tank, or last-minute raid-saver - both very circumstantial.
The arguments against it being brought up to full tanking have been that the Developers at Blizzard would have to balance this "new" tank class in with the others. Leaving it only as a light tank avoids this.
Or does it?
It avoids the problem only for one part of WoW: PvE.
In PvP it will still need to be balanced against other classes. Given the dramatic changes the glyph does to the class in terms of armour, health, and Demon Form abilities, it will still have to be considered for the effect on PvP balance.
I suspect the solution will unfortunately be just the nerfing of any abilities in the glyph form if they turn out to be an issue in PvP, until the glyph is just an oddity - used only in bizzare circumstances, if the Warlock in question even remembers they have it.
But my point lies, in that it will have to be considered anyway, meaning some of the effort in considering its balance will already be being done.
Secondly, as MoP is still in Beta, and given the Warlock class is undergoing a massive overhaul anyway, it's currently not too late for the potential of the Demonology spec becoming a full tank spec - doing away with the glyph completely.
Anyway, we can but hope.
I love the Warlock, starting mine the day World of Warcraft started. I played him almost exclusively until the Death Knight became available - far closer to my dream of a tanking death caster. I would switch back to my Warlock full time if I could tank with him in raids.