Afflication = Healer spec
Demo = Tank spec
Destro = DPS

Make it happen :p

Sorry, but to me, healing would just completely go against the whole idea of what it is to be a warlock: warlocks look out for themselves; it's all about getting more power regardless of the cost to others. We simply don't help people; it's not our nature.

Tanking, on the other hand... assuming a demonic form to wrestle with things that we should be far too weak to take on? Yeah, that fits a little better. As for Demo being a tanking spec, I'd be okay with that only if Blizz also left it as a DPS spec. However, they're clearly getting away from that, as evidenced by giving up on the DK "tanking in every spec" model, and splitting druid's feral tree into two separate specs.

So clearly, the right answer is for Blizzard to give us a 4th spec, similar to demo, with all the tricks and gimmicks we need to be true tanks.

C'mon blizz; you know you want to...

The thing about warlock tanking, Cheese, is that it would be totally awesome and unique among all classes because it goes against every precedent in the game. To elaborate:

First of all, nobody expected it. Then Wrath came along with Metamorphosis.

Back then, Metamorphosis was ( and still is ) a totally badaxe cooldown. But it had a lot more utility back in the day than it currently does. In addition to Immolation Aura and Demonic Leap, we also had Demonic Cleave which dealt a decent amount of melee damage ( yes, melee damage ), along with a fully functional taunt. Take all of those abilities, our ridiculously high threat generation, and an aversion to Soulshatter, put them all in the hands of a skilled player, and Metamorphosis could indeed be used to tank for a short time.

The intention behind the semi-tanky original design for Meta isn't entirely clear, but it probably had something to do with our innate ability to generate as much threat as most tank classes just by going through our normal DPS rotations ( even at the middle of the damage meters we had to Soulshatter a LOT ).

Those of us who enjoyed popping Meta and taunting in dungeons missed the taunt and cleave abilities when they were removed in Cata. There were other quality-of-life improvements to the Demo playstyle overall, but the utility was fun to mess with when we had it.

To answer the question of "why the 600% armor", given that Meta has moved away from the semi-tank cooldown it once was, I would say that it's there both for flavor and additional utility. In addition to the more flavor-oriented idea of demon form being harder to kill than clothie form ( which makes sense from every angle - I mean, it's a big cooldown, there's no reason for it not to be awesome! ), the Demo spec is well suited for soloing older content. It just makes sense to have that armor and crit reduction built in when you have elite trash packs hammering on you as you hellfire them all to ashes.

As to your comment that "If I wanted to play a tank, I'd make one", that's kind of a given. Every tanking class has the ability to DPS as well, and most do decent DPS in their tank spec and build. Feral Druids are ( until 5.0, anyway ) notorious for being able to dps or tank quite well with the same talent build and gear setup. If Demo tanking were ever implemented ( I seem to recall a blue post a while back stating that it's too much balance work at present ), it wouldn't be the only way to play Demo.

I say, give it a shot, Blizzard! I personally can't think of any reason why being a big purple winged tank ISN'T awesome.

Ah, whoops. I accidentally posted my reply as a new comment.