Source in case someone is willing to translate : 4gamer.net, the screen shot below taken from here.
The 700 series skipping the 600 series is just a rumor. It's base on a circulating benchmark that shows that the GTX 780 is twice as good as the GTX 580.
Source: Tweektown (Dated around 12/16-12/18/11)
Rumored GTX 780 spec (From VideoCardz.com , December 2011)
So, it looks like the Radeon 7000 series is gonna win the market the first half of 2012 and GeForce in the 2nd half of 2012, I mean for the gamers.
From what I've been reading on Semiaccurate, the GK10x (GeForce 6xx) parts will basically be a process shrink of Fermi, with some of the higher end models moving to XDR memory. GK11x will be Kepler proper. Apparently TSMC's high power 28nm process isn't ready for prime time, which is why the cost/Watt on all these near term cards is ridiculously high. GK11x will launch on the high power process, and AMD's high power refresh will come in 2013.
I'll be interested to see how the GF600s stack up against AMD as a value option.