Volume and other indicators disappeared in the classic desktop

from your screenshot, it looks like you have removed the indicator applet complete applet

Alt+Win+ right click the panel to add the applet. You can similarly remove the other gnome-applets.

If the applet doesnt appear in your list, install the applet from software-center:

or via the command line:

sudo apt-get install indicator-applet-complete

I had this problem too. Run gnome-sound-applet from the command line to check that it is installed and working.

To start the sound applet automatically, go to System Tools>Preferences>Startup Applications and add Command gnome-sound-applet

sudo apt-get install indicator-applet-complete

sudo apt-get install dconf-editor

than refer to the following figure to make visible the applets that you need.

Alt+Win+ right click the panel to add an applet.

There are two kinds of indicator applets. I dont know the exact translation, but there is a standard and a full version. Try the full version.

yes, same problem, maybe: http://code.google.com/p/volti/