Alright, so as stated above I'll be basing this editorial on what I see (and what has been FACT based) on what will happen in Guardians of the Galaxy.
The Premise:
There was a premise that was revealed before Guardians of the Galaxy that stated the following:
In the far reaches of space, an unlikely cast of characters including an American pilot and a group of futuristic ex-cons go on the run with a highly coveted object and must join forces to defeat a cosmic force of epic proportions.
The "Get Out Of Jail Free" Card
In the teaser that was presented at the 2013 San Diego Comic-Con, it was revealed that Drax and Gamora are inprisioned in some kind of interstellar jail.
It appears as though, through the footage revealed, that Rocket and Star-Lord will be breaking them out of Jail.
The Nova Corps Capture
In the footage presented at Comic-Con as well, it shows that all of the Guardians are captured by Nova Corps, and evidently enlisted to do something for them involving Ronan.
The Orb
It has been speculated that
The Orb that was featured at the 2013 San Diego Comic-Con will play a major role in the film. This has been verified as being TRUE! Kevin Fiege recently sat down and spoke with
SlashFilm and cryptically told them that yes, the Orb will have a part in the film. It is, indeed an Infinity Stone.
The Orb in question is, in fact, the
Time Stone.
The 80s, and Pete Quills Longing for Home
It has been speculated that Peter Quill longs for his home planet, Earth, or the longings of The 80s,
in the Guardians of the Galaxy footage, Quill is seen with a Walk-Man, and the song "Hooked on a Feeling" playing. I believe that he will use the Time Orb to go back to the 80s (for a brief period of time) to see his mother before her death. I believe this sequence will see Quill astral-projected back to when he was a baby seeing his mother for the first time.
The Thanos Quest, Ronan, Nebula, and The Collector
Thanos has been confirmed to have a role in the film, and more than a
Smirk and turn around as revealed by Kevin Fiege. I believe that Thanos will employ Ronan and Nebula to go after the Guardians to obtain the orb. Thanos' main goal in obtaining the orb is to have it so that he can go and steal the Aether from The Collectors vault/museum, or it may even be Nebula who goes after The Collector for the Aether. That part eludes me. The ultimate goal of Thanos' is to collect all the Infinity Stones to put those pieces in the infinity Gaunlet. I believe that the Collector has good intentions, but Thanos is pressuring him to obtain all the stones.....
The Human, Pete Quill, The Earthlings
Thanos' hatred for Earth has been seen in The Avengers, but his rage for killing them will be heightened in Guardians of the Galaxy soley because of Peter Quill, because he is an earthling, and he's the only one of his kind in the far reaches of space. He's an outsider.
These are all the speculations I have on the film, if anyone else has anything more to add please state it below and I'll add it here!