Well, there is one theme from the old movies that could be used in the Kotor games:
Jedi/Luke/Force (Don't really know what it's called..) theme should be used a lot more, it's the best piece of music in the Star Wars movies, imo. They didn't use it in the first game either, except in the intro movie. Obsidian should use it because it is the song in Star Wars which symbolizes The light side of the force, and 3 seconds of it isn't enough.