The Toronto Sun talked to Heath Ledger, who mentioned The Joker in The Dark Knight:
Come January, he starts playing the Joker, in Christopher Nolan’s next Batman film The Dark Knight. “It’s definitely going to stump people. I think it’ll be more along the lines of how the Joker was meant to be in the comics, darker and more sinister.”
The Toronto Star also got a quote from Ledger about the role:
I wouldn’t have thought of me, either. But it’s obviously not going to be what Jack Nicholson did. It’s going to be more nuanced and dark and more along the lines of a Clockwork Orange kind of feel. Which is, I think, what the comic book was after: less about his laugh and more about his eyes.
Warner Bros. is eyeing a June, 2008 release for the Batman Begins follow-up.