DailyTech has some information about the upcoming RS700 integrated graphics chip:
Since the RS600 uses a Radeon X700 derived graphics core it lacks support for DirectX 9c and Shader Model 3.0. Roadmaps show ATI will skip DirectX 9c support for its integrated graphics core and instead jump to DirectX 10. The next generation RS700 will have Shader Model 4.0, unified shaders, Blu-Ray and HD-DVD hardware decoding acceleration. RS700 will be built on a 65nm fabrication power for lower power consumption. Its expected RS700 will be a drop in replacement for RS600 as it will be pin compatible. Pin compatibility will simplify engineering times for RS700 as motherboard manufacturers can use the same layout for RS600 and RS700.
The RS700 will be available within a year and the RS600 will be available around August/September.