Batman Begins Director Chris Nolan talked with Better Than Fudge about the Dark Knight sequel:
"I suppose in loose terms I can say it’s about things having to get worse before they get better," he said.
What can be inferred about the Dark Knight title: "I’ll leave that for people to infer. The title has been chosen very specifically. It’s quite important to the film."
Regarding the Joker, which Nolan says will be like the Clown Prince seen in The Killing Joke: "Yes. I would certainly point to The Killing Joke but I also would point very much to the first two appearances of the Joker in the comic. If you look at where the Joker comes from there’s a very clear direction that fits what we’re doing very well."