That system will run BF2 great.
It's about the only game I play right now, I usually just play one at a time. I get great framerates at 1600x1200.
My system:
P4 3.0 w/HT, due for an upgrade
2GB of DDR400 (2GB does make a diff in BF2 over 1GB)
XFX 7800GTX (slightly faster than the normal one, but slower than the BFG OC one)
3x Cheetah 15k drives, RAID5 on an Adaptec Card
It's a pretty good little machine.
