Above is a video of Rally Master Pro and Bounce running on the Nokia N8. Rally Master Pro is a S60v5 game that was developed for the Sony Ericsson Vivaz. The game can be installed on any S60v5 device, but if your device doesn't have hardware graphics acceleration, it'll look terrible (as demonstrated here).
The game 'Bounce' is also shown, which is running very smoothly. I'll assume this is the Qt version of Bounce, as demonstrated by Nokia a few days ago.
This video (uploaded by Ahmed360) proves that the GPU in the N8 is at least comparable to the ones found in the Omnia HD, N900 and Vivaz.