As someone suggested in his post (in performance threads) I tried with lowering textures to med and adjusting almost all other settings to high and Voila!, I got massive improvement in performance. Now is playable. But the cost is high. Noticable uglier textures. So, they gonna need to optimize better the textures or we will need to wait 1-2 years for better hardware.
Btw I have i7920@3.5Ghz, GTX470 Twin frozr2 OC to 750Mhz on core and 6GB of DDR.