The Inq reports ATI's upcoming R580 will still be a 90nm part but later in 2006 we can expect a couple of 80nm GPUs:
ATI has three chips based on the 80 nanometre process. One is called RV560 and will be the replacement for the just-announced RV530, Radeon X1600XT. The second two chips are codenamed RV505 and RV535. We know that the RV535 is an RV530 chip based on the 80 nanometre design while the RV505 is a low end chip based on the same process.Read more over here. These GPUs will normally arrive by the end of Q2 2006?