I recently installed a fresh install of Ubuntu 11.10 64-bit on my notebook.
I personally prefer Rhythmbox over Banshee so I searched for and installed it from the Ubuntu Software Center. (including all plugins that were listed). Unlike previous versions of Ubuntu (11.04, 10.10, etc..) the (previous, play/pause, next) controls have been removed from the sound menu. Rhythmbox is still listed (above "Sound Settings...") but when clicked all it does is open the application. To add insult to injury the Banshee controls are displayed right above it - even though that application isn't running.
I have tried opening Rhythmbox from the Unity dashboard, the Unity launcher, and the sound menu with the same results.
I've also verified that I had rhythmbox-plugins installed.
I even tried to remove and install the application. Still no controls.
It looks like they were removed and that we are now expected to use Banshee. Why?
Here is a screenshot of what my sound menu looks like when I'm playing a file in Rhythmbox. (Notice that Banshee isn't running but it's controls are displayed) In Ubuntu 10.10 and 11.04 Rhythmbox had controls just like Banshee's controls in the screenshot.