In the actual comics of the '40s, Joker did come out of nowhere and didn't pick up an origin until years after the fact...and then it only went so far as to explain how he got the face, not to reveal who he really was.
On the general review topic, I found it to be a solid and engaging film, and gave it an Excellent
here, on the basis that in terms of letter grading, I would have given it a solid A, but not an A+. I don't think Superman
is in any danger of being dethroned as the definitive super-hero film. This one is far from definitive, it's more specialized, taking the existing genre to new places. It has the same flaw as BB, even moreso. It seems to have become popular to bash the Burton films somewhat...some even see them as "camp", when in 1989 the first film stood as a polar opposite to the Adam West TV show. I'd say they were more fantastic than camp, but whatever they were, they established a world in which you didn't have to suspend much disbelief to buy that a man would dress in big rubber batsuit to fight crime. This is where the Nolan films fall down flat. The titular character is the one thing that takes me out of these films. He seems to work better on paper--when Bruce and Alfred are talking about symbols and what he has to become, it works. But when we clearly see the guy in the big not-rubber batsuit, he just sticks out as being too unreal for his surroundings.