CoE is only useless if you have a moonkin in your group/raid. The reason being is one of their talents puts on a buff that increases dmg with every cast they do. I can't remember what it's called but since it doesn't stack with CoE you might as well not cast it and cast CoA or CoR instead.
I still take malediction though for the passive +3% increase in dmg.
I still take malediction though for the passive +3% increase in dmg.