This new model will replace the GeForce GTX 460, it has one SM less than the Ti model. It's expected to offer 336 shader processors, 56 TMUs, 32 ROPs, a 256-bit memory bus, and a core clockspeed of over 800MHz.
The card is expected to hit the market between mid-April and early May, it will fill in the 170-180EUR price gap in NVIDIA's GeForce 500 lineup.