Rumours put the GTX 960 at around $250-275 USD, a bit below the GTX 970's MSRP and more or less where the current 760 is selling at. It won't be too far behind the capabilities of the 970, although by how much is uncertain.
It won't be arriving until sometime next year, so no chance of getting it this holiday season.
How much do you think you'll be able to spend on the video card and PSU altogether? Both WoT and CoH2 seem to do well at ultra settings with a GTX 770, but unfortunately all three of those games both rely on a fair amount of CPU power, and it's hard to say exactly how well your i5 2320 will do. Your processor seems to be a weaker version of the popular i5 2500k and cannot be overclocked. Looking at other users' results, I get the feeling that the processor might be a bottleneck.