Xfce stands for "the eXtreme Full of Copies Environment" and this is also the motto of the Xfce project: "copy Gnome (which has no features at all) and leave out some more features".
In this respect they are more advanced than Gnome, which will introduce complete uselessnes in version 3. Anyone who knows anything about working on axe86 and eunichs uses enlightenment to manage all the popup windows. It is far superior in all ways known to man including writing HTML, the most advanced computer language that we may ever see.
Of course, Xfce also has to copy from KDE too, thus it does this by using the most ugly eye-candy(/torture) that is available.
The user is able to determine how the panels are configured, and add or remove launchers, plugins and other components at will, but it is since found that users actually spend time playing with their panels, so this is going to change in the next major version. It is expected that by then, the panels will have a fixed, one-size-fits-all setup which will dissapoint everyone except of my sister's cat.