XCOM: Enemy Unknown Pre-order Campaign Begins, System Requirements

A post to the official XCOM: Enemy Unknown website reveals that the pre-order madness for Firaxis' turn-based strategy/RPG has begun, with the PC version of the game now being available for purchase from Amazon, Steam, Impulse, and GameFly.  All digital re-orders earn you the Elite Solder Pack, and sweetening the deal on the Steam version is a free copy of Civilization V along with some Team Fortress 2 items. On top of that, we now know the minimum and recommended system specs:
Along with this announcement comes the finalization of the PC system requirements. A lot of our fans have been asking what these are so they can figure out if they need to upgrade before release day. Well wonder no longer for here they are:

Minimum Requirements:
OS: Windows Vista
Software: Steam Client
Processor: 2 GHz Dual Core
Memory: 2 GB RAM
Hard Drive: 20 GB free
Video Memory: 256 MB
Video Card: NVIDIA GeForce 8600 GT / ATI Radeon HD 2600 XT or greater
Sound Card: DirectX Compatible

Recommended Requirements:
OS: Windows 7
Processor: 2 GHz Dual Core (Intel Core 2 Duo 2.4 GHz or Athlon X2 2.7 GHz)
Memory: 4 GB RAM
Hard Drive: 20 GB free
Video Memory: 512+ MB
Video Card: NVIDIA GeForce 9000 series / ATI Radeon HD 3000 series or greater
Sound Card: DirectX Compatible