I don't know how you reached the conclusion that AMD is doing really well in graphics and the 7000 series "crushed" NVidia's 600 series. Aside from numerous inaccuracies in your analysis (for example, the 600 series was released three months after the 7000 series, not six - March 22nd 2012 vs December 22nd 2011), in most benchmarks Nvidia fared really well against AMD with equal framerates and lower power consumption/temperatures.
The 680 came out really quick, but was pretty much out of stock for about 2 months after it came out consistently.
But I'm talking more about the 77xx vs the 66x lines, which are the most mainstream discrete cards in the series, where the 77xx came out in February and the 66x cards came out in August. So about 6 months.
For all the hype around the 7970 vs 680, in the end the vast majority of their OEM card sales will be with less expensive hardware, which is why I think AMD "won" even if the 600 cards give better FPS for lower power usage in video games. They just basically controlled the market for mid-range cards for almost half the year, and by the price cuts they have been making they have been making a really sizable profit off sales until Nvidia brings out a competitor.
I just want to mention I'm not an AMD fanboy - I have an i7 920 and a gtx 285 right now. My "last" build was around 2006 and was an Athlon x2 with a 1950.
