There won’t be any new R600 or any other high end graphic card to fight Geforce8800 Ultra, at least not this year. ATI lost this year’s high end market to G80 completely but it will make money on the entry level and mainstream chips.
There is a new high end card that ATI works on based on two RV670 chips scheduled for early Q1 2008. We don’t know many details about it but two RV670 should make quite a fast card.
The point is to keep up until the R700 comes.