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.