To play devil's advocate, I think it's a lot more difficult to make a good Thor movie than it is to make a good film about Iron Man or Hulk. I've always considered the idea of Thor to be a hard sell, doubly so in terms of making a movie. It's very tricky to find the happy medium (if there even
is one) between a campy, live-action cartoon and an unrecognizable, "modern" update similar in name only.
EDIT: Spelling corrections..