It looks like the RV770 chip is coming along pretty well and at least according to this report could be out in time for Computex in June.
We learned that the RV770 GPU already went to production and there is a big chance to see R700 generation much earlier than anyone has expected. TSMC is already in pilot production and the chips are, as we reported earlier, developed in 55nm machitecture.

The way it looks now, there is a strong possibility that R700 should show its face at Computex (June 3) while the launch itself might be shortly before or after Computex. We still don’t have the final details.

RV770 is the based on the R700 design and the R700 itself consists of two RV770 chips. From what we know, RV770 should be at least fifty percent faster than the RV670.