I’ve been using Ubuntu 11.10 for a while now.  So far it seems okay.  It has a lot of improvements over 11.04.  The main problem that I have is that sometimes, especially when switching users, the system fails to switch to the GUI properly.  It normally isn’t a problem for me, as I know most of the shortcuts like Ctrl-Alt-F8 and stuff, but it isn’t good for my wife.  I hope that problem gets taken care of in 12.04.