I knew that The Dark Knight was not going to be an origin story of the Joker, but I expected Nolan to at least have quick flashbacks or cryptic clues given to the Joker's origin. Maybe such methods are still in the film to hint about the Joker's past, but Nolan's words leave me wondering what he is really up. He mentions that Joker's origin is thrilling and an important element but that he wanted to deal with Joker's rise not his origin. The Joker's origin in The Killing Joker, which is the definitive take on the Joker since there is no other acceptable origin, is what makes the Joker Batman's equal and opposite. Nolan not at least hinting at it, could really dampen the Joker's greatness. Hopefully Nolan will at the very least have some passing reference to the Joker's origin or hint at his origin being revealed in The Dark Knight. I mean the film does not need to be an origin story of Joker, to have his origin in it. It not in The Dark Knight I hope the next film will contain Joker's origin. See link below for details.
I am not much of a Batman fan in general, but I have liked some events in his history and also the Batman Begins and the first two Batman movies of the early 90's. I have not read the book in question but still find Joker to be very interesting, probably one of the best DC has to offer really. To be someones opposite you can either be born the opposite or forged into it.
I think Joker has established himself well as the opposite of Batman. Batman is rational and ordered. Joker is insane and unpredictable. Batman has trouble figuring out the Jokers next move and I think forh im thats not good. Joker is a crazy killer. I think thats enough really. I mean I have never gotten the impression that Joker can beat Bats hand to hand, although I am aware of several instances where he has done very well against him, but his mind and schemes are what get him by.
He is a killer and a monster. I dont see what could be more opposite. I mean in the end, for this movie he is going to be some really mentally deranged person who gets a kick out of killing and doing other things. A really sick dude. He was not designed or anything to fight Batman, but you dont have to be for two guys to not like each other. I mean straight up you have a guy dressed like a clown vs a guy in a body armor vest with gadgets and such. I mean a direct conflict should not go well for Joker. Although just from the trailers Heath Ledgers laugh is crazy.