Chris Pratt says it's possible in this interview with IGN:
IGN: James has said Guardians is a pretty self-contained story and it quite literally takes place far away from the rest of the Marvel movies. But Marvel’s into long-term planning and they’ve got all these interweaving of the movies and characters. Are you hopeful that a couple movies from now you might be teaming up with some Avengers and maybe fighting alongside Iron Man or Cap?
Pratt: Man, that would be really cool. What’s nice is that it is all the same universe. Because it falls under the Marvel umbrella, there is the possibility, just like in the comic books, that these stories could intersect.