Back in 2006, Sega purchased the rights to the Alien franchise. They then hired Gearbox Software(Brothers in Arms) and Obsidian Entertainment(Neverwinter Nights) to respectively develop a FPS and RPG based on the franchise. While all through out 2007 and most of 2008, there was not much released on the titles, Gearbox's title, Aliens: Colonial Marines, has recently come up with some new info. However, Obsidian's title has, for the most part, been left in the dark.
However, we recently dug up some new info of the title, and got some results. Developers on the game have stated "The team is definitely still hard at work on Aliens RPG", clarifying "We and SEGA will talk about the game when "it's time" to do so. I know that's annoying, but things shift around a lot during game development, especially with new technology. It's better for us and end users if we talk about the game when it's further in development. It helps avoid disappointment and confusion".
When asked about possible competition with Gearbox's Alien title, Obsidian replied "Ultimately, I think that the games help each other by raising overall consciousness of a brand that hasn't seen much attention in the past few years (outside of AvP)".
There is still no estimated release date for Obsidian's Aliens RPG.