YES! This feature ASTOUNDED me when I was playing Warhammer. And if WoW had it, disc priest would require 50% less clicking. This feature is a MUST for any hardcore gamer and any good healers from Warhammer would agree!
Any true hardcore gamer is going to do what he can within the limits of the game he or she chooses not demand the game changes to suit their whim. Sure, it'd be a nice addition, but it isn't a necessity.