Well, the 'Tank' archetype is not a 'WoW' type of tank, but more of the DAoC's tank.
If you never played it, PvP encounters usually happened like this: 2 groups collide, the tanks go after the casters, the casters attempt to immobilize the melee DPS/tanks/healers, and the Melee DPS were to kill healers.
Because the tank class consists of high defense and high hit points, it isn't effective to go after them, especially if they've got healers, but if the tanks aren't immobilized, the casters can't cast effectively.
It's a very nice balance of class systems and skills. If you don't have good communication and skills, you will lose the fight. If you don't have effective classes, but you have the skills, your chances of winning will diminish.
WAR is similar in this aspect, a major difference though is in DAoC, casters would stop casting completely if they moved or were hit, in WAR, this is not the case, so fights end up a lot more chaotic and require a higher level of skill to asses situations.
So, if your entire experience of MMOs is WOW, you really need to clean your slate of how MMOs *should* work.
WoW is an RPG plugged into the internet without a storyline.