Ubuntu plans to fork a separate Appearance panel this cycle so
that Gnomebuntu can use the GNOME Background panel.
I believe Ubuntu will try to use the Printers and Region & Language
panels instead of system-config-printer & language-selector
https://bugzilla.gnome.org/show_bug.cgi?id=687258
Add the X-GNOME-Settings-Panel category. You need a control-center
panel to add this to your desktop file. Desktop entries with this
category but that aren't actually panels will be ignored (no cheating).
If the desktop file for your settings isn't a panel, it will show in the
"Other" section of the control-center shell
https://bugzilla.gnome.org/show_bug.cgi?id=630998
