"There are no recommended specs as basically anything you have over this will run it nicely," Ubisoft representative UbiRazz wrote in the game's official forum.
Minimum System Requirements
Supported OS: Windows XP/Windows Vista
Processor: Dual core processor 2.6 GHz Intel Pentium D or AMD Athlon 64 X2 3800+ (Intel Core 2 Duo 2.2 GHz or AMD Athlon 64 X2 4400+ or better recommended)
RAM: 1 GB Windows XP/2 GB Windows Vista
Video Card: 256 MB DirectX 10.0-compliant video card or DirectX 9.0-compliant card with Shader Model 3.0 or higher (see supported list)*
Sound Card: DirectX 9.0 or 10.0-compliant sound card (5.1 sound card recommended)
DirectX Version: DirectX 9.0 or 10.0 libraries (included on disc)
DVD-ROM: DVD-ROM dual-layer drive
Hard Drive Space: 8 GB
Peripherals Supported: Keyboard, mouse, optional controller (Xbox 360 Controller for Windows recommended)
* Supported Video Cards at Time of Release:
ATI RADEON X1600*/1650*-1950/HD 2000/3000 series
NVIDIA GeForce 6800*/7/8/9 series
Thanks to Shacker Alpha for the heads up.