Windows 8 is upcoming version of Microsoft Windows Operating Systems as officially announced by Microsoft. Windows 8 should be released in 2012.
There is no official suggestion from Microsoft about minimum hardware requirements for windows 8 yet. But according to experts Windows 8 is not a hardware hog and Windows 8 would have same system requirements as that of Windows 7.
Below should be minimum system requirement for windows 8
CPU: 1 GHz or faster
RAM: 1 GB ( for 32-bit) and 2 GB (for 64-bit)
Hard disk: 16 GB (for 32-bit) and 20 GB (for 64-bit)
DirectX 9 graphics device with WDDM 1.0 or higher driver