I dont know if anyone has talked about this yet but I have heard a rumor about a spell called Reanimation. This spell allows you to bring back an enemy that you just killed and it will become your minion of destruction. I think that this spell would be cool. Go out and kill a daedric god and bring it back to life and let it reak havock along side you. let me know wat you think.
I am sure there will be a restriction on reanimation, such as only one NPC at a time, or of course a Duration like any other spell. However, it would be interesting to be able to reanimate a lot on NPCs.