Yes!!!!!! By far the greatest superhero of all time. I'm actually re-reading the Killing Joke right now, as it is possibly the greatest comic ever written.
As for the movie, I believe they want it to be more of a horror film because the Joker himself is all about random senseless acts of violence. I think I read Nolan say he sees the Joker as the shark in Jaws. It just cuts through scenes. And I'm glad, because if anyone has read the Killing Joke, it's a frightening, yet brilliant comic.
I'm more interested in what direction they will take with Harvey Dent. I think, at least with the way they are marketing it, they're taking the Batman: Year One approach as him not being a complete, complete villain, but more of a psychological villain/hero.