As Windows 7, codenamed Vienna is an improved version of Vista, DirectX 11 will work on both systems. It looks that DirectX 11 will launch before Windows 7 and we have high hopes of seeing DirectX 11 by the end of 2009.
DX11 is based on DirectX 10 but naturally it has more
options including Tessellation, compute Shaders - something good for Cuda and GPGPU, CPU
multithread support and some new texture compression. Let’s not forget Shader
model 5.0 but at this time we don’t know enough about it.
Tessellation might be the most important feature as some
developers are getting excited about it. Tessellation can subdivide objects and
give them better level of details and more polygons but we don’t know what
implementation Microsoft plans for DirectX 11.
The important thing is that despite being designed for
Windows 7, DirectX 11 will certainly launch before the new OS and at the same
time it should run well on Vista.