A good view on tanking
Blizzard has discussed in the past having some fights tuned to certain tanks. The comments from the official forums is now a little different, and probably a little more reasonable to many players. Instead of tuning fights to a tank, they are going to attempt to have each tank, tank differently, but still be able to tank most fights. Hurray!
Q u o t e:
So if Warriors are the best tanks for "bosses who hit hard for physical damage" (i.e., with the exception of elementals [where druids/pallies have no edge] and casters [again, no edge, although DKs have one], pretty much every encounter where the tank matters much), why not choose a warrior for every difficult encounter?
We've talked about this a lot, and I'll admit that it may not be the best way to go (designing tanks for certain bosses). Currently we are talking more about HOW classes tank, not WHAT they tank. Potential examples: The warrior tanks by having a shield, a lot of mitigation and avoidance. The druid tanks by having a huge health pool. The paladin tanks by using passive reactive abilities. That is a gross simplification, but perhaps you get the idea. This would naturally lead to some tanks being better at some fights, but it should leave more flexibility to the individual. Players won't count up all the bosses and say "Only 4 hit for magic damage, so we don't need a death knight."
You can find the original thread here.