Theres been some news just recently from both HKEPC and The Inquirer regarding ATIs next lineup of graphics cards due for release in the coming months, some of it purely speculative of course but interesting nonetheless.
Also with thanks to HKEPC, below is a picture of ATI's RV550 based reference card.
Replacing old weapons, ATi is going to finalize the specification and designation of RV560/570 in the coming weeks. RV570 is to replace X1900GT with the same performance but a lower cost. RV570XT is probably designated to X1900GT, same with R580GT, or a new X1950 family. With regard to the previous ATi's roadmap from Gecube, sources indicate that RV560/570 are neither 12 Pixel Shader Processor nor products based on RV530 (Radeon X1600 family) plus CrossFire Compositing Engine. In addition, to complete with nVidia 80nm G73-B1, which supports HDMI Signal Mixing and is expected in production in Q4, ATi is going to release RV550 to give HDMI Signal Mixing support to HTCP.