Because, imo, the 680 was always the 670. I think nVidia just pulled a fast marketing stunt with the 680. AMD had a solid product out and mostly available well before nVidia did- yet again. AMD was raking in the profits from the 7900s, just like they did with the 5800s. nVidia had to do something. So they launched a card that was the GTX680 in name only. I'm sure we'll not see any more 680s available for sale, or at least not in great supply. Prepare for a GTX685 instead that'll be much more deserving of such a name and asking price.