I think we need Smarter NPCs as in. ( The Fallen going on patrols around the map. Instead of staying in one area so it's always the same every time you going in game. ) ( when a group of fallen See there commanders drop dead they run away or beg for their life. Kinda like the grunts in Halo.) (More battle strategies like flanking, suicide bombers and Calling in reinforcements last second.) ( funny or serious interactions kinda like the Brutes pissing on a rock or tree. and grunts teasing each other or commands getting ordered.) I think if they did that the game would be much more Interactive even if your character is not interacting with them. Seeing it helps a lot. Making you judge your morals. Kinda like for me when I play a game and I see NPCs acting innocent to their own culture in game, I hesitate on whether to kill them or not. Just a few ideas of mine.
The A.I's get smarter as they level up. Plus we have only seen what the level 8 and some 9,10 A.I's can do, however I would Like for them I be a little more challenging I Can't image what the high level 25+ raid battles will be like.