The survey shows that for DX10 cards, it is 3.88% for GTX260, 1.47% for the GTX280, 0.78% for the GTX285, 0.64% for the GTX275, 0.58% for the GTX295. Amazingly, the 4800 series went up by 0.93% in the past month for the Steam survey.

Either way, it is 11.33% for the 4800-series vs. the 7.35% for the GTX 200 series so roughly a 3:2 ratio with regards to the Steam survey of 4800's sold vs the GTX200's