Do not try to install GNOME Shell in Ubuntu 11.04 Natty Narwhal from GNOME3-Team PPA, at least for now. I was trying to do just and ended up with a completely unusable Ubuntu now. Even PPA-Purge was not able to fully recover my Ubuntu 11.04. I should have really read this warning before trying to install GNOME Shell in Ubuntu 11.04.
This is What Happened
I wanted to give GNOME 3.0 (GNOME Shell) a try for sometime now and I decided to install it the supposedly easier way in my Ubuntu 11.04 Natty Narwhal. Alas, It proved to be a very costly decision. GNOME3-Team PPA won't work as is expected and it will totally mess up your Ubuntu 11.04 as well. That was my experience with the GNOME3-Team PPA anyways.
One other thing that I noticed was that, a lot of popular blogs out there recommend installing GNOME Shell from GNOME3-Team PPA without any clear warning. GNOME3-Team might update the PPA soon, but for now it is rather unusable. So beware.
Purge PPA Might be Able Help You
So if you already tried installing from the GNOME3-Team PPA and messed up your Ubuntu 11.04, PPA Purge might be able to help you, at least in theory. It didn't worked in my case. So here is how you install Purge PPA in Ubuntu and then downgrade the installed packages from GNOME3-Team PPA using Purge PPA.
sudo apt-get install ppa-purge sudo ppa-purge ppa:gnome3-team/gnome3
Hope it helps. Now, here is our listing of things to do after installing new Ubuntu 11.04 Natty Narwhal. You might also be interested in this collection of laptops and netbooks that comes pre installed with Ubuntu 11.04.