Ars Technica has a good article on-line detailing some of the new features being introduced with Microsoft's upcoming DirectX10. And of course, with a new version of DirectX on the way, expect all of the major graphics companies to have new GPUs to take advantage of the technology as well. Knowing you all though, ATI's R600 and NVIDIA's G80 will be the only two GPUs you'll care about.
"DirectX is an often-misunderstood platform. Introduced in 1995 as a way to convince DOS game developers to move over to Windows, DirectX provided an application programming interface (API) that developers could use to access many different aspects of the graphics, sound, and input hardware, without having to program directly to the "bare metal" of each individual card or chipset. DirectX incorporated many different subsets of these APIs, including DirectSound, DirectInput, and DirectMusic, but the component that received the most changes over the years was Direct3D, which followed the rise of powerful gaming graphics cards for the PC."