Here he discusses his thinking about the cast and crew should the books be adapted for the big screen:
I know a lot of authors "cast" certain actors in their books as the characters, but I've never done this. In my mind, they're who they are--and that's not a given actor. It's someone else, as unique as any of us are. That isn't to say I wouldn't like to see a director adapt my books to film! It just means that it is very hard for me to pick actors for my books.Learn more about the Mistborn books and Brandon Sanderson and his work at his website and his blog.
Now, directors are a different story. I've often thought about who I would like to make the Mistborn trilogy into a movie. The obvious choice would be Peter Jackson, but I shy away from this one. Perhaps because he's the aforementioned obvious choice. More, I've always kind of thought that I'd like to pick Robert Rodriguez. Why him? Well, because of his versatility. I've seen so many different types of movies from him, but I've liked every one. He's good with action sequences, can film a nice, dramatic scene, and has proven that he can do adaptations. Mostly, however, he's able to mix blockbuster storytelling with an artist's flair.
So, that would be my pick!