This is a lesser known Marvel comic. The Guardians of the Galaxy was initially introduced by Marvel in 1969, but there was a 2008 reboot that this movie is based on. Both versions of the Guardians have been included in the Avengers comics (including Iron Man having a stint as a member), so it's possible that Hollywood is testing the waters with Guardians to see if it catches on and an Avengers-Guardians mega blockbuster is feasible. I believe the purple alien at the end of the Avengers movie is also tied to the Guardians storyline.
I doubt it will be as successful as the Avengers, but still may be worth watching.