I think I may have just realized why super hero/comic book stories have transfered so well to film. Its part of why they were popular in their original incarnations as well. The costumes are a valuable edition to the mise en scene of the film. Mise en scene is a concept I've started to think about alot, its one of those undefinables in the history of film criticism.
But part of it has to do with the idea of Pure Cinema. What is convened to the watcher through the shot as opposed to the montage or the dialogue. I think truly Pure Cinema will include the montage as well. But Mise en scene seems to be what can make slow films (slow as in movement) like the Godfather films so effective. Particuarly the final shot of Godfather Part II or even in a faster film like The Dark Knight. And its also interesting that both of those endings have a heavy dose of montage as well.
But its interesting when you look at Iron Man or the Joker information has been transfered to you simply in their costume. That must be part of the mise en scene. And super heroes give us an incredible variety of costumes, something that is lacking in most other films. When Batman is looking across the interogation room at the Joker information is being convened about their characters as well as the story.