GNOME 3.8 released with classic mode similar to GNOME 2
help.gnome.org
help.gnome.org
(FWIW, I've been running it for a couple of weeks, and rather like it. A couple of the 'classic mode' extensions make gnome-shell a lot more usable (especially TopIcons extension which lets you have a useful taskbar), and it feels a lot more responsive than gnome-shell 3.6).
* n.b. not to be confused with gconf-editor, which has an equivalent set of settings which won't do anything (it's being deprecated)