The GK104-based GTX 660Ti is apparently slated for an H1 August launch and debut with a suggested price of $299.
According to Wccf Tech, the new card will arrive with seven active SMX units, 1,344 processing cores and 1.5 GB memory. The clock speed will below the clock speed of the 670 card, but the performance will be, according to the site, above the GTX 580 and directly competing AMD Radeon 7800 cards.
Wccf Tech also noted that the GTX 660Ti will be Nvidia's last GK104 card and the company will be transitioning to the 700 series going forward. At a price of $299, the 660Ti makes a lot of sense below the $399 670 and the $499 680 cards.