I think improving the AI in FPS should not be about making the enemies much mure clever and deadly at all. People play those to be able to kill hordes of monsters, not to be creamed by them. I think making them more "life-like" (ie. doing things that are not directly related to trying to kill the player in a clever way) would be much better. Like, getting hungry and looking for something to eat, taking a pee, etc. But that is hard to do in tight scripted games where you walk along the path and get monsters thrown in your face.
