They really need to stop making batman and superman movies....
Yeah, I mean, Batman Begins grosses almost $400,000,000 world-wide and is praised as one of the best Batman titles to date, so it would only be stupid to capitalise on its success and make another one.
Jack Nicholson's Joker = Jack Nicholson playing Jack Nicholson with white make-up. I don't necessarily think he did a good job playing The Joker, that's not as to say he did a bad job with the script he was presented, but The Joker is supposed to be a psychopath maniac, and Tim Burton made him look like a "heeheehee look at me dance" carnival clown.
If Nolan's joker is the psychopath he's supposed to be, and Ledger can pull it off, look out. Also, TDK's will be more true to the Joker story line as far as I know. Tim Burton's --
Jack Napier kills Bruce Wayne's parents, then Wayne becomes Batman, then Napier becomes Joker, thus creating instant tension between the two characters -- was made up for the purpose of the storyline. In the Batman world, Jack Napier never existed.