It's a great decision as both Nvidia and ATI Shader Model 4.0 parts are expected sometimes toward the middle of 2006, before Longhorn arrives. We don't have any idea what it is going to be called but DirectX 9.something sounds like a reasonable guess.
If Microsoft decided to wait for the Longhorn for those new shaders, this would have meant that the next generation Nvidia and ATI chips would have had to wait for a few quarters before they would be able to get the full Shader Model 4.0 functionality.
DirectX 9 update to add Shader Model 4.0 support
Posted on Monday, Sep 05 2005 @ 19:32 CEST by Thomas De Maesschalck