Fumbleknock has posted Blog Azeroth's next shared topic: Should WoW implement a new class that will break the tank heal dps trinity?
I'm not quite sure how I stand on this issue. It's a delicate subject, methinks, and if Blizzard were to create a fourth to the trinity, it'd have to be done very carefully, as there are not many options that won't make some aspect of the game overpowered.
Most people seem to think that the most likely candidate to fill this position would be some form of crowd-control class. The first thing that comes to mind immediately after hearing this is 2v2. Imagine a mage and a CC-class. The cc-class keeps the healer out of commission for the 10 or so seconds it'll take for the mage to destroy the other of the team. Game over. It might make raids safer, but sometimes the best time is had when we accidentally pull another elite or a group of mobs and we actually have to work to down the pull.
Another popular answer is a sort of buffer class, one to improve an aspect of the trinity. This can be easily done without making the class overpowered - Three talent trees: defense buffs, attack buffs, heal buffs. Maybe physical power buffs, magical power buffs, defense buffs. Something along those lines. The most popular selection for this would be a bard, but I don't think that would work for the sheer bore factor. A bard plays songs to buff, and therefore will be just kinda sitting there, playing a song. One, it takes no skill to hit 1 and let your song play. Two, few people in their right mind would want to play a class that requires you to hit one button a minute. This can be offset, perhaps, if you give the bard some healing ability that will allow them to heal in emergencies, but in the long run, I don't think it'd be a very fun class to play.
Still on the subject of a buffer class, we could make a not-bard. I don't know what we could call it, but it would work in a similar way with the talent trees. Contrary to the bard, though, the buffs can be cast and done with (much like warrior shouts, but probably much shorter), leaving the class some time to actually mash some buttons. I'm always leaning toward healing ability for a buffer class, but it could be dependent on what tree you choose, too. The healing buff tree will allow the player to off-off heal (not enough to completely replace a healer class), physical damage buff allowing them to get right in on the action and hit some things, etc. I'm really kind of liking this idea. The class has the potential to be very involved. Buffs that need to be re-cast often leave room to switch buffs (from, say, attack power boost to damage reduction boost) as needed.