This week of graphics driver testing in Fedora 13 is being led by the Nouveau test day beginning on Tuesday, the ATI/AMD testing on Wednesday, and then on Thursday is the Intel graphics testing. While these are the designated days, you can of course test the graphics on your system on any day this week and then report your results to the Fedora Wiki.
Those interested in participating don't even need to have Fedora 13 installed but can simply be running a Fedora 13 LiveCD. The Wiki links with all of the instructions are here, here, and here for the Nouveau, Radeon, and Intel days, respectively.
On each of these days Fedora's team is basically looking for feedback to verify that mode-setting works, RandR is functioning right, X-Video works, if 3D / OpenGL acceleration is functioning, and other features like fast-user switching / VT switching / suspend also work. For bonus points is multi-head testing and multi-head with a compositing manager.
The release of Fedora 13 Beta is also expected tomorrow. We'll likely be conducting some new graphics tests off Fedora 13 Beta in the coming days. While this graphics testing right now is all about Fedora 13, it will end up benefiting most other Linux distributions down the road considering the bleeding edge code that Fedora lives on and their upstreaming of work.