The NVIDIA ION platform boasts a GeForce 9400M (MCP79) graphics processor and it was not until today's commit that the PCI IDs were added along with some slight G80 hardware initialization changes.
This support is coming finally after an old bug entry with users desiring the GeForce 9400M support and several duplicate bugs too. The actual GeForce 9400M / ION support in xf86-video-nv is actually based in part on an idea by Ben Skeggs, who works for Red Hat and is actually one of the Nouveau developers.
Of course, like the other supported NVIDIA graphics processors, this support is limited to very basic 2D acceleration and not many other features. Those wishing to utilize the 3D support and other advanced functionality will need to use the proprietary NVIDIA Linux driver that long has supported the ION platform. Anyhow, the xf86-video-nv driver is certainly dieing and really does not hold much of a future with the Nouveau driver coming about and its kernel mode-setting support now being in the mainline Linux kernel.