Fedora 17 heads up: gnome-shell for everyone!

“As of tomorrow’s rawhide [1], gnome-session will no longer
treat llvmpipe as an unsupported driver. This means gnome-shell
will run even on hardware without a native 3D driver, including
virt guests.

There are probably bugs! I’ve done some quick tests on the
hardware I have handy and in kvm, and things do appear to work.
You, lucky contestant, might have a different experience. If you
do, bugzilla is standing by and ready to take your call; please
file against the ‘mesa’ component and set me as the assignee. In
the meantime you can still get to fallback mode through the
Graphics section of the System Info control panel.