AMD first has to release their R600, and they are currently struggling to do so, then mid-range and low-end pci-e, after that AGP. This is going to take a long time, and i want be waiting, i'll be ditching my AGP system soon.
if they wait much longer G90 will be ready to ship when the R600 is, this is worse for them than the R520 was, because they at least had a limited supply out in November 05 3 months after the G70, but G80 has been out since Nov, and R600 was pushed back to May, so Nvidia has 6 months to control the market, and will have midrange and low end by March, along with the 8900 cards to refreash and no word from AMD as of yet. I smell a problem there, i wouldnt wait on R600 if i was you, it looks like the Voodoo 5 6000 to me.