OpenGL is currently an industry standard for cross platform, hardware accelerated 3D graphics and it is also the only way to get fast 3D graphics on Linux. But it now seems that Windows Vista will seriously degrade OpenGL by implementing it via Direct3D.
"In practice this means for OpenGL under Aeroglass: OpenGL performance will be significantly reduced - perhaps as much as 50%, OpenGL on Windows will be fixed at a vanilla version of OpenGL 1.4, No extensions will be possible to expose future hardware innovations.
It would be technically straightforward to provide an OpenGL ICD within the full Aeroglass experience without compromising the stability or the security of the operating system. Layering OpenGL over Direct3D is a policy more than a technical decision."