The thing I'd love to see once Nolan is done with his "could-be-real" version of the mythos is a completely over-the-top, very faithful to the comics adaptation done with real actors but with an over-stylized, comic-book-on-screen feel to it just like 300.
Actually since 300 came out I've always dreamed of a similar take on Batman. I really do think it would work and rock. And you'd have no limit as to what you could film and show with that kind of movie.
I don't really think shooting every single scene of a movie in front of green or blue screens with minimal actual sets is a nice evolution in filmmaking, but I can definitely see that work for Batman.
It would really be a Batman comic book come to life.