That's what I also thought. I installed the flight simulator FlightGear and it's not playable at all, the framerate drops below 1 fps.
the nvidia kernel module seems to load fine.
nvidia0: <GeForce FX 5200> mem 0xfd000000-0xfdffffff,0xe8000000-0xefffffff irq 16 at device 0.0 on pci1
and kldstat says:
5 1 0xc07c5000 42b314 nvidia.ko
I couldn't see anything special in Xorg.0.log, it says the glx module gets loaded without reporting any error. You can find it here: