I think it'll definately amount to best movie of the year. I saw a midnight showing, (and then another a couple of days later....and I have it on my computer...), and I was blown away by it. I was also one of the people going to the theater skeptical, because the thought of Ledger once taking it up the ass onscreen, sickened me. But the guy made one hell of a good Joker. As far as I know, if the Joker is even in the next movie, it will only be as a shadow in a cell. And Nolan has already said the next movie will more than likely be the last, and Bale acknowledged. So we have one more gem to look forward to.
Edit: And it'll more than likely be The Riddler or Catwoman (or both) in the next movie.
It definately wont be Penguin. Nolan said so, and Bale threatened to quit if it was.
