The default theme during installation is Raleigh, but after rebooting it
reverts to gtk-default.
I am not sure how this is considered a bug. The raleigh theme is just a theme
that is used with the installer. There is currently no setup during the install
to choose if the raleigh ( or any other for that matter) will be the default
theme post install. The gtk-default theme has always been the default theme
since Gnome became standard in the red hat distribution. You can choose the
Raleigh theme from the theme selection menu in the Gnome Control Panel if you
want it to be your default theme.