#25 - Oct. 15, 2009, 8:50 p.m.
I don't think it is required. Everyone's definition of required is going to vary quite a bit but very few mods are actually required in my experience.
Building an in-game UI to handle paladin buffs is something we would like to do for Cataclysm (then again, so is "overhaul every aspect of the game.")
It was once a goal to make every class UI the same. Since the DK, and more recently the shaman and to a lesser-extent the druid, and then soon the warlock, we've been moving away from that.