Since we first heard whispers about 'Prometheus', it's been hidden behind and extremely thick shroud of secrecy, and not much has changed other than a few possible spoilers and plot details that have "leaked" out.
According to the site MarketSaw, a very trusted site of theirs has revealed how 'Prometheus' will fit into the 'Alien' universe. As I said, these spoilers definitely fit in with what we've heard from other sources so far but either way, take them with a grain of salt for now.
Possible Major Spoilers Ahead
"Ridley Scott’s sci-fi movie, currently going by the name Prometheus, is going to be a very large and intense story, with a scope that is epic, the final act is where the movie switches gears and shifts into Aliens territory. Pinewood houses an exact replica of the H R Giger Space Jockey command post. You may notice in the original Alien that the Space Jockey had a puncture on its considerably large chest, where the xenomorph broke out through the flesh of the creature and broke through the biomechanical armor it wears. You may also notice how big the Space Jockey is in relation to its human counter parts in the film. So imagine how big the baby must be, which is yet to grow. Then imagine quite a few of these. If you can do that, you got a pretty good grasp on the final act."
On how the xenomorphs will be different from the previous films:
"And do not be expecting the traditional look either, these are very different creatures that will keep the general architecture of the xenomorph, but will have a considerably different look, and do very perverse things.
And here's the last bit of spoilers for you guys:
"However, before all of this I hear that the story is not only reminiscent of 2001, but is also trying to push the boundaries of what a modern tent pole science fiction movie could be. This is all I can share, but trust me, you seriously need to start being excited about this project, because not only is this I am assured, not nostalgia for nostalgia reasons, but a whole new spin on that old chestnut … The story is a very closely guarded secret in Hollywood, and while it is not a direct prequel “officially” it has more than just passing ties towards the Alien saga’s canon. You will have all the things that worked in the Alien canon, and very new and fresh and some controversial ideas presented, sexuality is dealt with quite directly. There may even be a robot or two. And the ship, which I am told is the current titles name, Prometheus. Highly original, both in concept and design I hear."
Prometheus is scheduled to hit theaters on June 8 ,2012.