The volume icons in xfdesktop don't show an "Eject" menu entry for volumes that support it, because it also has to be a disc.
The attached patch removes the check for a disc and also disables the "Unmount" entry when "Eject" is enabled, as suggested by bjt on the Xfce ML. This makes the volume context menu consistent with Thunar.
Created attachment 1463
enable "Eject" menu entry for volumes that support eject
Fix checked into trunk, rev 27951.