According to Movie Pilot on Feb. 22, it appears that Marvel's "Guardians of the Galaxy" trading cards seem to give away the plot line. Could Robert Downey, Jr. be rendezvousing with "Parks and Recreation's" Chris Pratt in the end credits scene of "Iron Man 3"?
One can only speculate, but one of the trading cards do show Iron Man in the space suit version of Stark's armor, which pretty much confirms the possibility of him being in the movie. Also Jason Momoa was close to being Drax the Destroyer, only to have Marvel move on to more auditions. Gamora, Rocket Racoon, and Groot are yet to be even cast. Though it is rumored that Adrianne Palicki of "G.I. Joe: Retaliation" may play the part of Gamora.
One might wonder if Nick Offerman, who plays Ron Swanson on "Parks and Recreation", might be a good fit for Groot. After all, considering his character on the show, Swanson's past or future life could be quite "Groot-like" in character. He's very close to nature and especially wood. Swanson is also the City of Pawnee's Director of Parks and Recreation department.
Now that the Iron Man character has embedded itself into main stream pop culture, he now has a huge following among those who probably weren't comic book nerds before. Currently taking the gamble by writing Stark into the "Guardians of the Galaxy" would indeed be a good move for Marvel as it was such a similar risk with "The Avengers".
The cards will come out in parallel with "Guardians of the Galaxy #1" comic book by writer Brian Michael Bendis and artist Steve McNiven.