The Inquirer heard from its sources that ATI's third R520 tape-out was successful. The first tape-out failed because on average only 20 chips per wafer worked like they should. A wafer costs roughly $3000 so ATI needed a second and even a third tape-out to lower production costs.
The Inq also claims that the R520 core will run at 600MHz or higher and that graphics cards based on this chip will likely be launched in September. This will give NVIDIA a 2.5 month lead as their GeForce 7800 GTX is already available in quantity.
ATI will have a hard time and it's likely that NVIDIA will already launch a faster version of its G70 by the time that ATI launches its R520.