Meaning these are the minimum requirements, at this time. It will most likely change once the game is close to being finished.

Processor:
AMD Athlon 64 X2 Dual-Core 4000+ or better or Intel Core 2 Duo Processor 2.0GHz or better
Operating System:Β 
Windows XP/Vista/7
RAM:
Windows XP: 1.5GB
Windows Vista and Windows 7: 2GB
PCs using a built-in graphical chipset are recommended to have 2GB RAM
Graphics Card:
ATI X1800 or better*
nVidia 7800 or better*
Intel 4100 Integrated Graphics or better*
DVD-ROM:
8x or better

via: WorldSims