The Expendables 2 isn't even out yet, and their now casting the third movie.

"We’ve approached Clint Eastwood to be one of the guys, we’ve got a character in mind for him. We’re talking to Harrison Ford. [And we want] Wesley Snipes when he comes back from prison. I’ll give you one more name, we’ve got Nicolas Cage to play [one of the characters]. And we’re going to bring Mickey Rourke back, if he won’t be too crazy. I like Mickey. And of course, all the existing stars [will return]."

It appears as if Nicolas Cage (who worked with The Expendables 2 director Simon West on Con Air) has already signed up to play a character possibly called, 'Hunter Gatherer', although their recording apparently wasn't clear enough to pick up his name. The site also reveal a major spoiler about the fate of Jean-Claude Van Damme's 'Jean Vilain' in the sequel, and address the chances of him appearing in the planned third instalment (you can find all of that by clicking on the link below).

I can see Clint and Ford. Snipes is kinda pushing it, but please not Cage.