I just played the first 10 Minutes to check the Performance with my GTX 460 on my PC. Rest of the System is an FX 6300 @4,5 GHz, 8 GB DDR3-1600 RAM, 120 GB SSD.
Even with Fraps is it playable and always around 25 fps, without Fraps even more.
My GTX 460 is still performing ok. :) Anyway, next month I´ll buy an AMD 7870 or 7950. :)