I have learned a lot of inside information, and upon realizing how true it was I stopped reading.
I all ready know more than I wanted to and I won't spoil it for anyone else by telling. I'll just let it be.
But to give a general outline in keeping more with what's all ready known; the Joker (Heath Ledger) is the main villain and proves to be a major threat for both the police and the underworld of Gotham. Harvey Dent runs for District Attorney, and there appears to be a romantic attraction between him and Rachel Dawes. Mob bosses go to war with each other, with Scarecrow in the mix. Vigilantes following Batman's example (but with more violent methods) further contribute to make Gotham one nightmarish place to be! In times of desperation, the underworld turns to the Joker for leadership. I didn't read the storyline far enough to know, but I'm guessing that Harvey Dent becomes Two-Face by the end (although I'm assuming that we won't actually get a decent glimpse of him until film three.)
It promises to be more epic and intense than the first one, and more violent. The Joker's psychology is just as well developed as Batman’s. Like the first film, the first half of this one is mixed with flashbacks to develop character depth. Batman has a new uniform (his underarm blades can now retract, and even shoot!) His neck armour is changed so he can move his head better (why past Batmans keep their head straight in the movies.) I think we'll all be more than pleased!
Here are some 'leaked' photos:
There are more, but trust me, you wouldn't want to know too much!