The card, apparently designated GTX 595, packs two GF110 cores and it will be quite interesting to see how Nvidia and EVGA managed to cope with the thermals. EVGA used a massive heatpipe cooler with no fewer than three fans, but we still don't know the clocks. We can only assume that the clocks are somewhat lower than on the GTX 580. There is no word on price, availability, or the amount of memory for that matter.
However, it's worth noting that AMD's dual-GPU Antilles board is also just around the corner. While the Cayman is marginally slower than the GF110 in a single-GPU environment, it's worth noting that AMD might have a bit more room to tinker with the clocks thanks to slightly lower TDPs, so Antilles could come a bit closer to the GTX 595.
We will probably have to wait until mid-Q1 to see GTX 595 and Antilles cards in action, but we're really not sure they are worth the wait. Both cards will draw a lot of power and generate obscene amounts of heat and we doubt many current games will benefit from the extra performance.