Ubuntu Vibes reports that the Ubuntu classic Gnome session option is no longer available in Ubuntu 11.10

Now for the updates, Ubuntu Classic is no more an option in GDM. Earlier, Ubuntu and Ubuntu Classic were available as default Gnome session options but after today's update, it is only 'Ubuntu' now. The changelog also confirms this:

+ gnome-session

       - depends on unity, unity-2d or gnome-shell, and nautilus
       - suggests only gnome-session-fallback (we don't want it to be installed  by default)

So, the classic panel layout (or Ubuntu Classic) as fallback session will not be installed by default. If a user wants to use the classic panel layout, gnome-session-fallback will have to be installed from repositories. 

  Ubuntu 11.10 Updates: Ubuntu Classic No More an Option in GDM