Saw this just now
Geforce GTX 660 / Ti
Nvidia's next-generation 28nm GPU architecture, codenamed Kepler, is officially expected to launch in early Q2 2012 according to the latest schedule we have seen from the company. Although the company will technically be launching one quarter behind AMD, we can still expect to see a few noteworthy design wins in the enthusiast and performance segments, beginning with GK110 in April and following up with GK104, GK107 and GK108.
The latest report from sources overseas claims that Nvidia's GK104 GPU, the successor to 40nm GF114 (see: Geforce GTX 560, Geforce GTX 560 Ti), will feature a 256-bit memory interface, will pack 2GB of memory capacity and should have a 225W TDP. Nevertheless, the GK104 will most likely be branded as Geforce GTX 660 and may very well have a Geforce GTX 660 Ti variant later down the release roadmap.
Many analysts are expecting 28nm GK104 to get a big boost in CUDA cores. Some estimates are projecting as many as 768 CUDA cores or "well above 2 teraflops" of raw performance, which roughly equates to 50-percent more compute power than the current flagship Geforce GTX 580 single-GPU card with its 1.56 teraflops. While we don't have exact information on these specifications yet, we expect more information on the exact details of CUDA cores, texture units and ROPs in the very near future.
Looks like the GK104 is going to be a solid midrange card to replace the GTX560 series, but even if it packs more shaders and increases it's single precision math ability to 2+ terraflops, the HD7970 has 3.7 terraflops, and the 256 bit memory bus also means less memory(2 GB) and less memory bandwith too, so this is no direct competitor to the HD7970....
That leaves the GK110 wich is a dual GPU card according to rumors, but in any case the cards will only start showing up in april so it's still 3 months out...