This page defines the changes, if any, to the default GNOME Shell in Ubuntu.
As GNOME shell is still in very early stages, its appearance is far from finalized. A document containing the design guidelines can be found at http://www.gnome.org/~mccann/shell/design/GNOME_Shell-20090705.pdf
GNOME Shell features a redesign of the desktop. The top bar looks similar to the old, though the left hand side now has 'Activities' which opens an overlay for opening applications as well as maintaining desktops.
There is no longer a bottom panel, this area will be used for notifications
GNOME Shell also needs more exposure. Right now it seems it's only being seen by other developers and not the average user.
Gnome Shell is in beta so this is not advised unless you understand what you are doing. These instructions have been tested in lucid but could work in karmic.
To install Gnome Shell open a terminal and enter:
sudo apt-get install gnome-shell
To test the gnome shell interface press alt + F2 and enter:
To return to your previous setup just log out and log back in. If you want to change to use gnome shell as the default every session enter this is a terminal:
gconftool -s /desktop/gnome/session/required_components/windowmanager -t string gnome-shell