I just read this article and found this synopsis,
Spoiler
Synopsis: The film is supposed to start in the year 2058, where an archaeological dig reveals that humans were genetically designed creatures by Space Jockeys, an alien race. The Space Jockeys also made it so that Earth was habitable. The dig reveals the coordinates to the aliens' home planet, and the Weyland Corporation send out a ship called Prometheus to make the first contact. When the crew reach the planet, the aliens welcome them, proud of their creations, and the aliens tell the crew about their bio-based technologies. Of course, someone in the crew thinks there just isn't enough being revealed, so he decides to steal the "bio-source" code, the thing that the alien gods have used to create life. However, the gods do not think the humans are equal to them, so they unleash a monster they use to "clean up" the worlds before colonization. However, the humans manage to turn the monster on the aliens, creating smarter, more uncontrollable creatures that could destroy "Paradise". The members of the crew who manage to escape board the Prometheus and leave the planet. However, one alien god has survived and is intent on destroying Earth.
Read more:
http://www.shockya.com/news/2012/05/21/new-prometheus-tv-spot-hits-the-web/#ixzz1vVhiDYHD