I installed Ubuntu 11.04 on my DELL inspiron mini 10 last night. A message poped out saying ‘The hardware does not support Unity’ when the machine rebooted after the installation finished 
The reason is that the Unity (the new desktop UI adopted by Ubuntu in the latest version) can only run on the supported hardward – 3D capable video card.
To get a chance to experience the new UI, I installed Unity 2D which is the 2D version of Unity.
sudo add-apt-repository ppa:unity-2d-team/unity-2d-daily
sudo apt-get update
sudo apt-get install unity-2d-default-settings
Here is how it looks on my mini:
Jackie Chen's IT Workshop 
I very much recommend you do not use Unity 2D from the ppa. The Natty Repos have the most up to date edition available there. However if it is working well for you you might as well leave it alone.
It is good to know. Thanks for the info. I will try it when I get a chance.