Chris Baker, the manager of Marvel's video games, had a sit down with IGN to talk about Marvel's alternate costumes. He talks about Pheonix, Storm, MODOK, Dormammu and Captain America. My personal favorite is Punisher Cap.
For a more in depth talk about it, head over to IGN here to read the full article. I have yet to read it all, but I will once I get the chance. I had no idea some of these costumes existed. And Marvel did an excellent job with the alternate costumes by what I've seen.
The Cap pictures also reveal the return on the MvC2 character select stage, as noted by his Commie Cap color.