Currently getting an average ~45FPS @ 1920x1200 with High settings in the mod, running on:
Phenom II 965 Black @ 4x3.6GHz
ASUS M4N75TD
4GB DDR3 Kingston HyperX Blu
WD 750 GB Caviar Black SATA-II 7200 RPM 32 MB Cache
2x GTS-250 512MB in SLI
Windows 7 Ultimate 64bit
Nothing terribly fancy, nothing overclocked. This is a HUGE improvement from my old setup (dual core AMD 4400+ with 4gb of DDR1), but before the memory controller on the old board died, I got about 15FPS. When the failure occurred, I replaced the CPU, memory and motherboard (and did a complete reinstall just for good measure) and now I have no problems with this or really any other game I've tried. The whole upgrade including shipping was about $350.