I love this movie!!! It's the first movie to really impress me in a long time. I wish Heath Ledger was still around to do the next movie, but they'd better leave the joker out, no one could measure up to Legder
Christian Bale actually said he didn't want a robin so I don't think it's likely to happen.
Overall id say Christopher Nolan has done a fantastic job reinventing batman and hopefully there will be a third with a cast just as carefully picked.