Unlike most superheroes - Batman, under his disguise, is still a man - a wealthy man, but still human. He relies on his physical ability for his actions, and his money for his gadgets. Except maybe The Phantom, no superhero, is at his core just another human.
I went to watch it on IMAX - an experience in itself; especially the scenes with city scapes. It took some effort however - I went last night also, but the cancelled the late night showing, but neglected to tell anyone ...
I thought Batman Begins was the best superhero movie - this is far superior. And it is not only because of Heath Ledger. First and foremost, the story was good - well paced, and cruel; just as the concept of the Joker was meant to be. Without spoiling the storyline - when was the last time a major character in a superhero movie was killed by the villain? How about, when was the last time more than 2 major characters were killed directly or indrectly by the villain?
But the masterpiece in the movie is the Joker. The Joker proves the superhero movies do not need meglomaniacs or super-powered villains - all it needs is a psychopath. Heath Ledger's Joker is in the same realm as Hanibal Lecter - a psycopath killer who is in it for the game; and not the result. And Heath Ledger is awesome - utterly believable; so completely engrossing, that you cannot really picture him as anything else. And that is the hallmark of great acting IMO.
In all probability there will be another Batman movie - but what villain could possibly rival the Joker? And yes, IMO Heath Ledger should get the Oscar.