This is a very good paper about AI-Based Animation. I believe their method can be used to generate some advanced combat animations like what you can find in Batman Arkham Asylum and Assasin's Creed III. By applying it you can find best transitions to other existing animations based on direction of control and smoothness of transitions. This can give a great diversity to game by selecting best suited motions with fluid transitions at any state the character goes. Their method creates better and more responsive transitions from what you can achieve from motion graphs.
James MacCan, Nancy Pollard ,"Responsive Characters From Motion Fragments" In Proceeding of ACM SIGGRAPH - 2007