The new Fallout New Vegas DLC, Dead Money is now available on Steam. You can pick it up at the official steam page. Here is some information about the DLC.

Key Features

• Take part in a suspenseful post-apocalyptic casino heist in which you’ll need to work with three companions, each of whom has their own motivation for helping you.
• Add hours of extended gameplay where you’ll encounter the mysterious Ghost People, pre-war death traps and the holographic security system of the Sierra Madre.
• Navigate your way through a challenging new storyline, with even tougher choices.
• New perks, achievements, and a raised level cap to 35!

About the Game
As the victim of a raw deal you must work alongside three other captured wastelanders to recover the legendary treasure of the Sierra Madre Casino. In Dead Money, your life hangs in the balance as you face new terrain, foes, and choices. It is up to you how you play your cards in the quest to survive.

Story
Welcome to the Sierra Madre Casino! The casino’s mythical contents are lusted after by desperate wasteland scavengers, who tell stories of intact treasure of the old world buried deep within its vault. Lured here by a mysterious radio signal advertising the long-awaited grand opening of the casino, you are thrown into a high stakes game where you’ll have to work with three other lost souls if you want to survive.

System Requirements
OS: Windows 7/Vista/XP
Processor: Dual Core 2.0GHz
Memory: 2GB RAM
Hard Disk Space: 10GB free space
Video Card: NVIDIA GeForce 6 series, ATI 1300XT series