Firstly be warned - This game is going to require an internet connection at all times.
The game will be one of the first to introduce a new form of Digital Rights Management for Ubisoft games known as the Online Services Platform. The service requires players to authenticate the game at start and remain online while playing, if network connection is lost the game would automatically pause.
Take a look at Squee's recent review of Ubisoft's Assassins Creed 2 as he mentions the DRM a fair amount there.
System Requirements are as follows
# Operating System: Windows XP, Windows Vista, Windows 7
# Processor: 2 GHz Intel Pentium 4 / AMD XP 2600+ or better (Intel Core 2 Duo / AMD Athlon 64 X2 recommended)
# RAM: 2 GB (4 GB recommended)
# Video Card: 256 MB DirectX 9.0c-compliant, Shader 3.0-enabled video card (512 MB recommended)
# Sound Card: DirectX 9.0c-compliant sound card
# Hard Drive Space: 8 GB
# Peripherals Supported: Windows-compliant keyboard and mouse
# Internet Connection: Broadband Internet connection with 128 kbps upstream or faster
# Supported Video Cards at Time of Release:
# NVIDIA GeForce 7900 / 8 / 9 / GT / GTS / GTX series
# ATI Radeon X1900 / HD 2000 / HD 3000 / HD 4000 / HD 5000 series
# A permanent internet connection is required to play the game.