Xfmedia remote plugin enables control of Xfmedia media player via a Xfce panel icon. It includes ability to control playback (play, pause, stop, etc.) and playlist (add/remove songs) and more.
Xfmedia remote plugin is available from Xfce Goodies SVN repository: http://svn.xfce.org/svn/goodies/xfmedia-remote-plugin.
There is currently no Xfce Bugzilla component for Xfmedia remote plugin, so meanwhile bugs can be reported via email to firstname.lastname@example.org.