Gnome 2.0 still not appearing in the login screen ?

Hey all, following Richard Bos' instructions, I've been using apt-get to install Gnome 2.0. As far as I can see, it's installing things just fine. However, in the login screen, there's a Gnome option. It's Gnome 1.4, still. How do I get Gnome 2.0 to be available as an option at the login screen ? Jacob