Team Green is hard at work on their Kepler GPUs, which are based on a 28nm process, and it seems as though the GK104 part is going to be called the GeForce GTX 670 Ti.
NVIDIA is obviously keen to get this part onto shelves now, to combat the GCN-based AMD Radeon HD 79x0 parts, and this could be way the otherwise mid-range SKU has been changed from what should've been the GTX 660 to the GTX 670 Ti. This move could be so that it indicates this part will perform competitively against the high-end parts already on the market, such as the HD 7000-series.
Sources have told SweClockers that they expect the GK104-based GeForce GTX 670 Ti to outperform the GeForce GTX 580 and Radeon HD 7950. techPowerUp are reporting they're hearing rumblings of a March launch, and if NVIDIA want to beat the HD 7800-series launch, they'll have to wave that Team Green flag, now.