Mickey Rourke will star in Iron Man 2 as Whiplash.

Scarlett Johansson makes a sexy appearance as Black Widow in the sequel.

Both these roles have been hyped to death online, while Sam Rockwell has gone relatively unnoticed.

The actor takes on the part of Justin Hammer in next summer's blockbuster, and he revealed a couple tidbits about him in a recent interview.

"He's a rival to Tony Stark and he's an arms dealer and, you know, he's in cahoots with a couple of people.  He’s kind of a shyster," Rockwell told MoviesOnline. "I think he’s essentially he's a fan of Tony’s, but he doesn’t get the attention he wants from Tony and that's where I think it starts to go wrong for Justin a little bit."

Rockwell did say he thinks Hammer and Stark are similar.

"I think that ultimately Justin is probably more insecure and so that might be his downfall. And his ambition may be stronger in a way.  So it’s a trap that Justin might fall into."