Games I have tested:
Half-Life: Ran fine
Call of Juarez: Runs on DX10 with lower framerate, very slow loading of levels, levels loaded much faster and game ran better on DX9, very playable at around 30 fps
Spelunky: Ran fine
Eldritch: Ran fine
The binding of Isaac: some weird glitches when in the options at first, but once everything was set it ran fine
Aliens Vs Predator Classic: Ran fine
System Shock 2: gave an error about card not being supported, but reboot and ran okay
Alpha Prime: ran at 30ish with dips into teens at full quality, 40ish with some effects turned down or off
Serious Sam 2 - Framerate in the 20s at max settings, in the 40s-50s at medium with some settings turned low/off
Serious Sam Classic 1st encounter - framerate all over the place, from the 100s to the 40s
Call of Duty 2: can hit 30+ on low at 1280x800, but dips into the 20s. Steadier fps at 1024x768