Sure on Ubuntu 11.10 I installed Gnome 2.2 (see below comment for correction) as follows. This may not be possible on the next Ubuntu release. That's why I am migrating to Mint.
How to install gnome-classic on Ubuntu 11.10
# apt-get install gnome-session-fallback
# cd /etc/lightdm
# gedit lightdm.conf change user-session=gnome-classic
hold down the alt key when right clicking the menu bar to add frequency and system monitor
applets.
Yeah, but at what point does that stop the "power users" who seem to hate Unity from installing Gnome themselves? Hell, I removed Gnome entirely and replaced it with Xfce once. It's still Linux. Just because it comes with Unity preinstalled doesn't mean you're stuck with it.
Mint will be running "Gnome 3", the framework, but not "gnome-shell", the user interface. Unity itself is similarly just a interface atop Gnome 3. Mint will be running its own new environment called "MGSE" (mint gnome-shell extensions), which is basically gnome-shell customized to look and behave like Gnome 2, because that traditional desktop experience is what most current users want and can get neither with Unity nor gnome-shell, which both have basically abandoned their traditional desktop user base and are now betting their future on tablets.
Gnome 3? Not if you do want incremental improvements to your desktop environment but don't want a fundamental paradigm shift from installing the latest updates. If MATE takes off, maybe that will be a viable alternative.
I am capable of installing and uninstalling packages with apt-get, so I am not heavily dependent on Ubuntu to determine the UI for me. And I have no problem changing UIs (I used to use Enlightenment from DR13 or so)
So when a default changes away from something designed to look like Windows XP, I do not get emotionally scarred. I gather this is unusual, however, and Ubuntu's user base consists mostly of people who are terrified of package managers and can't abide anything except an XP ripoff GUI.
Maybe someone should start a new distribution which is premised on providing Ubuntu 8.04 in perpetuity.