In a move that should benefit netbooks and other ultraportables, Microsoft has a new system in Windows 7 that allows for Direct3D / DirectX 10 and 10.1 to be run directly through the CPU rather than a dedicated 3d hardware accelerator in certain instances (you could see it as graphics acceleration through the software). Microsoft is calling it WARP (Windows Advanced Rasterization Platform).
CPU-wise, all that will be needed is an 800MHz faster (and it will benefit from multi-core CPUs that also have SSE 4.1, although neither is a requirement). As Custom PC points out, it won’t replace dedicated hardware, but it does mean that the 3D interface will be available in just about anything running Windows 7 (some netbooks can’t currently run parts of Microsoft Windows Vista’s Aero interface).
Read: Custom PC
– MSDN article on WARP