After upgrading to Ubuntu 13.04, the tray icon for Quod Libet is missing. How can I get it back?
AFAIK 13.04 doesn't allow tray icons any more.
You can enable the Quod Libet MPRIS plugin (called "MPRIS D-Bus support") to make it show up in the sound menu.
Quod Libet 2.5 also adds unity quick list commands. You'd have to use the PPA to get that: