Bad for pvp imo, seeing which healer has pvp gear and which has pve helps me decide which one should be taken out first. With the changes from Wrath to Cata and pvp gear and pve gear now giving the same amount of health how will you be able to tell what the weak link is in the enemies team?
Also saw somewhere above about not allowing changeable appearence effects in rated bgs, definately need here aswell.
If they wanted to make it work better, only allow pvp gear to be changed into different pvp tiers/sets, and pve gear only changed into other pve gear, would solve this issue. But tbh can't wait to make my warrior appear in full 270 wrathful, awesome