ALTHOUGH MICROSOFT STILL still hasnt launched DirectX 9, which perhaps its reserving for November and Comdex, news reaches us of an upcoming change to the application programming interface
DirectX 9.1 will not bring the new [Pixel] shaders that should be implemented in hardware that will be launched at the end of next year. Insted Microsoft will introduce brand new Pixel shader 3.0. it will also include bug fixes and improvement of existing things in DirectX 9,
This time DirectX 9 hardware will have full support for all DirectX 9.1 feature. To clarify things for you, Radeon 9700 Pro and NV30 when it comes out will be DirectX 9.1 hardware. You wont see any new pixel shader supported in hardware than version 2.0, which is used by Radeon 9700 PRO.
If you ask why Microsoft wants to introduce Pixel Shader 3.0 before hardware supports it, it is to give time for programmers to learn about this new shader model before hardware and possible speed up its acceptation and transition process which is indeed a painful path.
News source: The Inquirer