i am running a rather powerful system so it isnt the best indicator for everyone but i havent seen anyone else post their system performance
System:
Vista Ultimate SP2
Core 2 Quad Q9550 2.83Gh (overclocked to 3.2Gh)
4Gb RAM
Nvidia Geforce GTX 285
Settings:
Resolution - 1980x1020
AA - 4x
Vsync - On
Shadow detail - High
Graphic Detail - High
i have played through the first mission only so far and for some reason my FRAPS wasnt working with it, it was however perfectly smooth gameplay through the whole mission, i was not able to notice any drop in framerate
controls needed some configuring to suit how i like to play, i am using keyboard and mouse, but that was easily done