My sys:
Dual Athlon 1800
Tyan Tiger Mobo
512mb DDR (going to 1GB DDR ECC Registered once I get home and get my mail

)
GeForce3 w/ 21.81 driver from 09/01 (the new 23.11 detonator gives me a parity error and BSOD)
SB Live 5.1
Win2k Sp_2
I turned all the bells and whistles on, running 32-bit 1280X1024, Trilinear w/ texture compression. I'm getting a slowdown in open areas and during big firefights. It's not too bad, but I wish it wasn't like this. I also see a lot of graphical errors...like occasionally if I peek around a wall, some textures won't be loaded, etc.
I'm going to try w/out texture compression. Maybe also turn off some extras (detailed smoke, etc).
Oh, and why do explosions look so pixelated and nasty?! Is that just me? After RtCW I was in awe of a great fire effect...MOH fire/explosions seem to suck, unless it's just me...