After booting the 201204 RC live CD the desktop defaults to Mate (I think). Is it possible to test Gnome 3 and Cinnamon without installing. I have tried logging out of the current session but the session login option does not display.
OK Found that by logging out of session, choosing other to log in will give the session options Cinnamon, Mate, Default. Select which you require and then cancel. Log in as Mint and the new desktop will load.