This week the Khronos group, which is responsible for developing and maintaining OpenGL, has released a report indicating that OpenGL support will now be natively supported in Vista without layering over Direct3D. Using standard Windows installable client driver (ICD), OpenGL will be fully accelerated and be fully compatible with Windows Vista’s Aeroglass UI. In fact, Khronos says that by the time Windows Vista ships, Aeroglass performance on OpenGL will be superior to that of Direct3D.
Performance is to be better using OpenGL, however the user is required to download the ICD manually in order to take advantage of it. At this point, anything that helps Vista run smoother is quite welcomed.