Fedora 15 is gearing up to be another great release from the Red Hat camp with new features like Linux power management improvements, full systemd integration, SPICE support for virt-manager, and consistent network device naming, among many other features. When it comes to open-source graphics drivers, Fedora tends to be on the leading edge of development seeing as Red Hat employs some of the key developers like David Airlie and Jerome Glisse. With Fedora 15, besides shipping with all of the latest kernel / X / Mesa bits, there is one interesting change that's gone largely unnoticed from their feature lists, etc...
Fedora 15 is using 2.6.38 kernel RC releases, and kernel-2.6.38-0.rc8.git0.1.fc15 is available in fedora-updates-testing repo, if you have F15 Alpha installed.
I recommend people install kernel-2.6.38-0.rc8.git0.1.fc15 at least, to get fixes for various issues. My
ATI cards have issues that seem specific to the default -rc5 that work in other 2.6.38 release candidate builds.
I am happy with F15 Alpha, but I haven't pushed it too hard against the recommended tests.