Bethesda Softworks have announced a new Fallout game, Fallout: New Vegas, for PC, Playstation 3 and Xbox 360. The game is in development at Obsidian Entertainment (Alpha Protocol, Neverwinter Nights 2, Knights of the Old Republic 2), a studio founded by some of the original Fallout developers.
The details are scarce at this point, but Bethesda is obviously looking to build on the success of Fallout 3, while the Fallout 3 team presumably focuses on the next chapter in the Elder Scrolls series. And everybody seemingly is a winner.
On a personal note this announcement takes me back to E3 last summer when Obsidian's Feargus Urquhart visited the Bethesda booth when I was there. He played a bit of Fallout 3 and talked to executive producer Todd Howard. I guess there was more to that meeting than I knew at the time.