I installed gnome-shell on a fresh Ubuntu 11.10. Worked wonderfully, so much better than Unity (personal opinion)

Then I decided to do an update. After rebooting, logging into either Unity or Gnome results in a login sound and my wallpaper. No window manager, no panels, nothing but a cursor.

I also have applications crashing on startup (under gnome2d) with error messages complaining about names not found in .service files.

I have seen the same errors in my .xsession-errors log.

Can somebody please help me get my desktop back?