What they need to work on FOR REAL in future AC games is the whole "being an assassin" thing. I like how things are now, but you should be able to, maybe in certain missions, play as an actual assassin instead of as a tank. I want to climb up a building, eliminate some guards, OPEN A WINDOW, sneak inside the hallway, make my way to his room, stab the sleeping noble, set the place on fire, bust through the window, land on my horse, and run off to my hide out.
Basically, I want to do stuff like in the AC1 and AC2 CG trailers! I want to sneak, kill, run.
With the BAM system it could make for some great assassinations were multiple targets must be killed at once. I hope they evolve this system in the future.