First Appearance: Marvel Preview #4 (1976)
Abilities: Half alien and half human, Peter Quill can fly, survive the pressures of space without a traditional space suit and has a limited healing factor (it is unclear how he gained these powers or if they are just from his current suit).  At one time he had an implant in his left eye that let him see different energy spectrums and a memory chip that provides him with 100% recall (it's assumed these won't be in the film).  He uses a number of weapons including a "meta-pistol" which fires one of the four elements (earth, air, fire and water). He also uses more conventional alien weaponry when necessary.
Chances he's in the movie: 99%
Lowdown: Potentially the only Earth-born member of the team, Star-Lord is also lock because of his unique powers, skill set and because his most recent costume and mask is begging to be recreated on the big screen.  He's also the usual leader of the team and, well, a bad ass.