I've been using Fedora 15 since its release (it was a fresh install) and have run the built-in updater three times; the third time being just earlier. In running it, about 113 updates were found, and afterwards, I rebooted. Unfortunately, GNOME 3 somehow broke as a result of that update (I didn't do anything else system-wise in the meantime), though I'm not sure what could have caused it.
After logging in, I see nothing except my desktop wallpaper. The top bar doesn't exist, and there are no workable elements... a wallpaper and nothing but. Thinking it might have been a user issue, I created a new user under Xfce and then logged into it, and I had the same thing. Default wallpaper but nothing else.
I am actually in the process of reviewing Fedora 15 (and GNOME 3) and was nearly done writing what I needed to before this happened, so I'd love to figure out a way to fix it rather than reinstall the entire OS since I have things set up to my liking and would hate to have everything undone.
If it helps, I did a yum groupremove of "GNOME Desktop Environment" and then a groupinstall of it again, but that didn't help it either. It did ironically remove both KDE and Xfce I had installed, however.
Any help would be appreciated!