I've searched the forums, and didn't find anything regarding this. I'm thinking it would not only apply to Brutallus, but to the whole of Sunwell, and even BT/MH.
There is an item that drops in SMV from Overseer Ripsaw, called
[Illidari-Bane Shard]. It adds 45 ap/185 spell damage when fighting demons, but I can't really remember if it goes into a trinket slot, and if it has a cooldown. I've opened a GM ticket, and hopefully I'll get somebody who knows what this is about. I'm thinking that if this is a passive increase, it might be the best trinket for dpsing demon bosses?