Ridley Scott has announced that the Alien prequel movie project he has been working on for the last year or so has been reconfigured into an original film.
It was originally indicated that Scott would be helming two movies set before the events of the original Alien, revealing the backstory of the 'space jockey' aliens and how they came to have a ton of xenomorph eggs in their cargo hold. However, after pre-production headaches (including the apparent loss of the second part), a major rewrite by Lost scribe Damon Lindelof convinced Scott to transform the movie into a stand-alone film, unrelated to the Alien franchise.
The new film, now entitled Prometheus, is expected to go into production shortly. Noomi Rapace (Lisbeth from the Swedish Girl with the Dragon Tattoo movies), originally hired when it was still an Alien project, remains attached as the lead and the release date of March 2012 still stands. I assume it's still in 3D as well.
As a long-term fan of Alien and Aliens, this is good news. Whilst a new Alien movie by the original director was intriguing (and the implication that it might retcon the Alien vs Predator movies as non-canon), some of the ideas sounded a bit odd. At the end of the day, we don't really need every t crossed and every i dotted on the backstory of the xenomorphs, and people really into this stuff would have already found the various explanations given in the novels and comics.
A new, original Ridley Scott SF movie - his first since Blade Runner - sounds like a far more interesting prospect.