spoilers, so if you read, it will be spoiled.
It was pretty good. Really good actually, if you discount some unnecessary messiness at the end and an incredibly stupid oopening act.
The bit is Hong Kong is James Bond level stupid, and i wish Nolan had the good sense to keep the juvenile spy novel fantasy elements in this section out my juvenile comic book fantasy movie. To open a movie as unrelentingly dark as this one with a bit that involves a CIA plane airlifting Batman out of Hong Kong with a money launderer in tow is surprising, considering the tone has to reset itself after this. Once the Joker enters however the movie really finds its groove, and Heath Ledger's turn here (and more surprisingly the ability of the rest of the cast to melt down in their own ways around his gravity) is good enough that the opening is quickly forgotten. The middle bit is the best bit, mostly due to the Joker.
The less said about the moralizing ending, and the seven hours of dumb speeches about whatever, the better. Spinning the movie away from its best element towards a tacked on villain was, uh, not so good. Making point after point about it was even worse.
Definitely better than Batman Begins, which set a generic villain against a generic hero. At least here everyone was given a chance to play off of each other.