Having switched to Xfce from gnome one of the main annoyances I have found is having two separate settings GUI's for setting the theme, one for the window border and one for the controls/icons ( and yet another for the cursor theme )and neither include thumbnails!
As I like to switch themes and mix and match this soon became VERY irritating hence this BASH script and helper program, as you can see from the screenshots only one GUI is used to set all the bits of a theme, the "Themes" tab contains themes that have an integrated window border/control theme ( and if there is a gnome-like theme.index file that specifies an icon set this will be used as well ), everything is fairly self explanatory just click on a thumbnail to set a particular theme/window border/control/icon set.
Full installation/usage is in the README file in the archive, this is very much beta software and there are a number of improvements/additions to come.
http://xfce-look.org/content/show.php?content=149647
What do you think?