Download the rpm here
Install it with (as root)
yum install gnome-shell-extensions-theme-selector-0.9-2.fc15.noarch.rpm
the package no longer contains any themes, but i have made separate rpm packages for many great themes made by half-left.
The theme rpm's can also be used with the latest version of gnome-tweak-tool (3.0.4) (Not in fedora yet, but i have an rpm here)
the theme-selector extension cant reset to the default theme, this can be dome by running
gsettings reset org.gnome.shell.extensions.user-theme name
here are review requests for getting the packages into fedora.
Feel free to review the packages :)