Ubuntu 11.10 Oneiric Ocelot will use Unity (with Compiz) as the main session and Unity 2D as a fallback mode for those computers which cannot run the Compiz-based Unity. GNOME Shell will be (well... is already) available in the Ubuntu 11.10 repositories and can easily be installed, but how about the classic GNOME desktop?
Well, you can use the classic GNOME desktop in Ubuntu 11.10 Oneiric Ocelot, but it will be the GNOME 3 classic desktop and not the old GNOME 2. To use it, install "gnome-session-fallback" using Ubuntu Software Center, Synaptic or use the command below:
sudo apt-get install gnome-session-fallback
Then log out and select "GNOME Classic" at the LightDM login screen.
Once logged in, if you want to add some applets to the panel you must use ALT + right click instead of just right clicking it like it used to be in GNOME 2. Also, some of the old applets won't work in the new classic GNOME.
Here is a screenshot on how the GNOME3 classic (fallback) mode currently looks like in Ubuntu 11.10 Oneiric Ocelot (using the default Ambiance theme):
Update: to get all the Ubuntu indicators to work with the classic GNOME 3 session, see: Indicator Applet Ported To GNOME 3, Can Now Be Used In Ubuntu 11.10 Oneiric Ocelot Classic GNOME 3 Session.
What will you be using when Ubuntu 11.10 Oneiric Ocelot will be released? Unity, classic GNOME, GNOME Shell or maybe switch to XFCE (like Linus did) or KDE?
Post inspired by AskUbuntu.