This should be fun. Assuming Robert Downey Jr. as Iron Man, Jackson as Fury and Norton as Hulk, who would you cast as the rest? My list:
Captain America: Ryan Gosling. I know what most of you will say--too skinny. But remember--everyone said the same thing about Michael Keaton for Batman. And can you imagine him sharing a scene with RDJ? Fucking awesome.
Hank Pym: Sam Rockwell. Great actor that would blend well with the cast, and give Pym's neurosis a very interesting turn.
Thor: Kevin McKidd. I know he was rumored to do it but now word is that they're casting younger and want him for Loki, but fuck that. He'd be great in the role, and Iron Man shows that you don't have to make a character younger for people to want to see it.
Janet Pym: Not sure yet.
Make the movie about their discovery of Captain America, and the Avengers versus Red Skull. Then use the movie to spin out a Captain America movie and anything else. Captain America won't sell overseas as itself, but as a spinoff from a huge blockbuster, it'll have legs.