I just saw The Dark Knight, (spoiler alert!) so my thoughts might be a bit scattered. But I think I can sum them up thusly: it's a very good superhero movie, but it's not a very good movie. As Geoff Klock notes on his list of favorite films, the best of the genre have yet to earn their spot on an undifferentiated list of great movies. Two fundamental problems kept the material from elevating the production to something more:
1) Its seriousness. Most of the characters in this film talk like incredibly earnest philosophy majors, and the closing sequence is actually the most egregious part in the way that it allows Batman to pontificate ('Harvey wasn't what Gotham deserved but it's what they needed. Batman isn't what they need but it's what they deserve.' Uh, come again?) over a steadily building score in the most melodramatic way possible. Relatedly, the Nolans seem discontent to allow us to figure out what the various characters symbolize: half the script seems to be devoted to discussions of heroes, villains, and the politics of representation. This is the stuff of academic papers - whose authors are notorious for their over-seriousness, naturally - not of action films.
2) Its pessimism. The scene with the boats aside, this movie seems to regard everyone with doubt and suspicion - Batman doesn't even trust himself. In a clever-if depressing-rewrite of The Killing Joke's conceit - where the Joker tortures Jim Gordon in order to prove that even the best of people can be broken - we end up realizing near the end that the Joker's goal has always been to turn Harvey, to show that even Gotham's 'white knight' could be corrupted. In The Killing Joke, the Joker is proven wrong; in The Dark Knight, he's proven right. And not only is he proven right, but Batman takes the fall and Gotham is left with its white knight crazy and dead and its dark knight a pariah. Super.
There's some redemption, though, in Heath Ledger - he's what makes this a very good superhero movie, if not a very good movie. I didn't initially think this would be the case - I disliked his look, especially the scars on the face and the make-up. But given the rave reviews, an anonymous commenter asked me just yesterday whether I was prepared to eat my words. And while I'm not sure that I necessarily have any to eat, since I was only commenting on his appearance rather than the performance that I could not have seen, I can say that I was surprised by the complexity of the character for at least three reasons:
1) He's actually exactly the character that I had described in those old posts as the one that I wanted to see. In one, I note that the Joker should be the ultimate hysteric, who makes a demand upon his foes to tell him who he is and, in so doing, becomes exactly the villain that they want him to be. The writing is particularly strong when we see the Joker go through the process of rewriting himself, as when he tells a different origin stories for his scars. This could easily lead to the same long-winded pseudo-philosophizing that I criticize above, but...
2) His counter-philosophy actually undercuts the rest of the film. When the Joker explains that he's the anarchy to the good guy's reliance on planning and order, he risks falling into their categories and neat little cosmology. Except that it's a lie - the Joker, true to his excessively Rube Goldbergian nature - explains this just as we're realizing that his every action has been directly or indirectly aimed toward driving Harvey Dent totally fucking nuts. The Joker isn't scary because he operates without rules, but rather he's scary because his obviously pathological dependence on rules reveals how every rule is arbitrary and our dependence on them equally pathological. (This is also why Dent's arbitrariness as Two Face is a nice addition, though it's far less developed.)
3) Lastly, he's funny, and a film like that needed more of him. He cross-dresses, cackles, and channels an evil Woody Allen in casual conversations. All of which seems fantastically appropriate.