Fedora released Firefox 5.0 along with a recompiled Gnome Shell that linked against js instead of xulrunner.
The end result is that gnome-shell will not start. I can downgrade to the older gnome-shell, gjs, firefox, and xulrunner packages as a workaround for the time being.
Using the nouveau driver, I can use the latest packages without a problem.
When using the NVIDIA driver I get the following from gnome-shell:
(gnome-shell:3985): Clutter-CRITICAL **: Unable to initialize Clutter: Unable to
find suitable fbconfig for the GLX context
Window manager error: Unable to initialize Clutter.
Affected NVIDIA drivers: