Sort of an Alien prequel, sort of not. Wikipedia explains:
"Prometheus is an upcoming science fiction film directed by Ridley Scott and written by Jon Spaihts and Damon Lindelof. The film stars Noomi Rapace, Michael Fassbender, Guy Pearce, Idris Elba, Logan Marshall-Green and Charlize Theron. The plot follows the crew of the spaceship Prometheus in the year 2085, as they explore an advanced alien civilization in search of the origins of humanity.
Conceived as a prequel to Scott's 1979 science fiction horror film Alien, rewrites of Spaihts's script by Lindelof developed a separate story that precedes the events of Alien, but which is not directly connected to the films in the Alien franchise. According to Scott, though the film shares 'strands of Alien's DNA, so to speak,' and takes place in the same universe, Prometheus will explore its own mythology and ideas.
Principal photography began in March 2011, with filming taking place in Canada, England, Iceland, and Spain. Prometheus is scheduled for release between May 30 and June 8, 2012 in various territories through 20th Century Fox."
Whatever it is, it looks intense. I'm sure Pat Collins will love it.