I think the main source of the game being easy right now is poor AI. If they make the AI a lot smarter, some of these encounters could be much tougher.
I think I would absolutely hate for the AI to get "smarter" by leveraging some of the current structural weaknesses of the game, frankly.
Last thing I want is a group of enemies leapfrogging all around my party to avoid AoO and backstab my characters, for instance.