You probably mean Bethesda giving Obsidian a change ;). Seriously thought you probably mean Fallout: New Vegas.
Following details are known (courtesy of [url=http://fallout.wikia.com/wiki/Fallout:_New_Vegas_FAQ]The Vault Fallout: New Vegas FAQ[/url]):
Production and release details
General
What is Fallout: New Vegas?
Fallout: New Vegas is a futuristic post-apocalyptic RPG set in an alternate universe based on 50s sci-fi pulp fiction, as if the world had stopped during the optimistic 50s and found itself in a dystopian post-apocalyptic reality. It will make use of the gameplay style of Bethesda Softworks' Fallout 3[1], however, with a brand new story and setting.
Is it Fallout 4?
No, Fallout 4 will be a separate future project that will likely be developed by Bethesda Game Studios itself. For more information, see: Fallout 4 FAQ.This will be a Fallout spin off.
Will it be a MMORPG?
No, it will be a Single-Player game, like previous Fallouts. However, Interplay licensed the rights to a Fallout MMORPG from Bethesda in 2007 and is currently developing it under the codename Project V13. Bethesda recently moved to rescind the Fallout MMORPG license, claiming that Interplay is in breach of the licensing agreement. Interplay disputes these claims. For more details, see: Fallout Online FAQ.
Is it some kind of add-on?
No, unlike the add-on packs, it will be a standalone game.
Will it feature exclusive add-ons/DLC, like Fallout 3?
It is not known at this time.
Will it use the Fallout 3 engine?
Not officially announced, but given that it has been announced that it will be the same style of game as Fallout 3 and given the tight schedule, it most likely will.
Who is making and publishing Fallout: New Vegas?
Fallout: New Vegas is being developed by Obsidian Entertainment and published by Bethesda Softworks.
What is Fallout: New Vegas rated?
To be announced. However, Fallout 3 was rated M (Mature) by the ESRB in the United States and 18 in the UK, and New Vegas will likely have the same rating.
Release date(s)When will it be released?
The game will be released in 2010.
Platforms
What platforms will it be released for?
Like Fallout 3, the game will be released for the PC, Xbox 360 and PlayStation 3.
Will it require Windows Vista?
Fallout: New Vegas will work on PCs running either Windows XP or Vista.
Development team
Is it being made by people who made previous Fallouts?
Yes, it is being developed by Obsidian Entertainment, which was founded by some of the people who worked on Fallout, Fallout 2 and Van Buren at Interplay/Black Isle Studios.
Who is on the team?
The known developers so far are:
J.E. Sawyer - project director and lead designer
John R. Gonzalez - lead creative designer
Akil Hooper - designer
Scott Everts - designer
Theresa Treadwell - associate producer
Which other Fallout developers are at Obsidian?
Other people at Obsidian who worked on previous Fallout games include Chris Avellone, Feargus Urquhart, Chris Jones, Chris Parker, Darren Monahan, Brian Menze, Jesse Reynolds and Rich Taylor. At least some of them are likely to be on the New Vegas team.
Gameplay
Combat
Is the combat turn-based or real-time?
The combat will likely be real-time, with the active pause VATS system, similar to Fallout 3.
Other gameplay questions
Is first or third perspective used?
While nothing has been officially announced, given that it has been announced to be the same style of game as Fallout 3, it will likely allow you to use both first and third-person perspective.