It's a completely new game being developed by Obsidian.
The Vault said:
Fallout: New Vegas is an upcoming role-playing video game developed by Obsidian Entertainment and published by Bethesda Softworks. While New Vegas is not a direct sequel, it will use the same engine and be in the same style as Fallout 3, and is being developed by some of the people who worked on previous Fallout games at Black Isle Studios. It will be set in and around post-apocalyptic Las Vegas. It has a projected release date of Fall 2010 and will be available on the PC, Xbox 360 and PlayStation 3.
So, question for you all - New Vegas may be using a background system like the one in Dragon Age. So, how many of you are going to go with the Chinese Commando background, which makes you a ghoul?
*EDIT* Here's the info on that Chinese Commando. Spoilered for those who want to wait and see.
One background story is shown, Chinese Agent. The background story takes place before the bombs fell. The player is part of a team of Crimson Dragoons infilitrating Hoover Dam. You manage to sneak through the Americans’ defenses, set explosives, and head to an extraction point, but your escape is cut off by American soldiers in Power Armor. The player and other survivors of the Crimson Dragoons take refuge in a cave in the canyons, where they commit hari kari with cyanide capsules. The player about to do the same when the bombs fall. The background story ends an indeterminate time later, when the player exits the cave, removes his helmet, and sees his ghoulish reflection in the waters of the Colorado River.