Bruce is quite a mess already, but yeah, I agree with Papa Burgundy that it would be interesting to see more of his mental breakdown in the next movie. But really, the guy is becoming a total mess in the head. A really cerebral villain like the Riddler could utilize that if he learns about it.
He's got like... three personalities/acts that are becoming more and more jumbled up together. These are:
*****ebag Bruce - this the public persona, the face that most of Gotham sees, but is actually the most passive and unimportant personality. He's basically acting like an immature billionare playboy.
Batman - this is an act that was meant to be a symbol of anti-apathy, then became a secret persona in order to protect Bruce's loved ones from reprisal and then became a personification of Bruce's childhood fears and hatred towards the criminals. It's clear that at first this is just an act and Bruce is in control, but the more time passes by, the more the act becomes a distinct personality that can suddenly switch itself on in case of danger (when he talked to Rachel with the Batman voice) or can go in autopilot if there is no need for one of the other personalities to come out (when he talked to Fox with the Batman voice).
Serious Bruce - this is the real man. He shares this face only with the people he trusts - Ra's, Alfred, Rachel, Fox. Although he tends to add strokes of it in *****ebag Bruce (when he publicly supported Dent, adding a thin layer of altruism to the playboy) or in Batman (when he speaks to Gordon or Dent, even though he uses the voice and appearance of Batman, the thoughts are clearly Serious Bruce's) and some characters that are close to him sometimes tend to think that he is sometimes losing himself in the Batman persona.
I think that Bruce is more messed up than, say, Dent, but unlike him he hasn't exploded yet. If they touch on that in the next movie, it's gonna be interesting...
I would enjoy seeing that but it's already kind of there kind of, it's just not a big issue. I get what you're saying, that they should expand upon it, but I don't think it's necessary. I like how you have to really think about it, before it becomes clear what the true persona is, something like a higher level of film interpretation.
Alright, if they find a way to make it work without cramming too much into the movie, I won't be disappointed.