A sneak about the Performance of the GTX 960 ... Two Variants will be available ( one with a 128 bit Memory Bus and the Second with a 256 Bit Memory Bus (Ti) - both will have a 4 GB DDR5 by Default , the Ti version actually super-pass the GTX 780 with a sub 300 Tag Price , so two 960 in SLI with a Maxwell Architecture will have a brilliant performance/value Ratio. I think with the 960 release , it will be a nail in the tomb of the 7 series (Kepler) and AMD's 2xx Series (the 280x and Even the 290 which is above USD 300). With the 960 release serious thinking to upgrade is recommended :)
My Advice for those who want to upgrade now , wait until the Release of the 960 (Especially the Owners of the 760 , 770 , 670 ,680 , 280 , , 270)
http://wccftech.com/gtx-960-ti-benchmarks-specs-revealed/