Don't shoot the messenger
http://www.semiaccurate.com/2010/02/17/nvidias-fermigtx480-broken-and-unfixable/
...the short answer is that the top bin as it stands now is about 600MHz for the half hot clock, and 1200MHz for the hot clock, and the initial top part will have 448 shaders. On top of that, the fab wafer yields are still in single digit percentages.
http://www.semiaccurate.com/2010/02/17/nvidias-fermigtx480-broken-and-unfixable/