It's Fedora Graphics Test Week
It's basically a matter of checking to ensure basic functionality on a wide range of Intel/NVIDIA/AMD hardware is working properly for the open-source Linux GPU drivers. Testing is quite simple and there is also a LiveCD image available.
This Fedora 15 Graphics Test Week is even more important this time around to see how these open-source graphics drivers are playing with the GNOME 3.0 SHell / Mutter.
For those interested in helping out, stop by Adam Williamson's blog for the testing details.