To be honest I'm not overly impressed with the UI. It isn't all that great to navigate and seems clunky. They have in fairness made for a less pain free experience in terms of 'install and go' with a lot of features working straight out of the box.
I was also bit surprised that it has not been able to detect my Nvidia GTX 275. This is something previous Ubuntu versions never had issues with.
The Ubuntu Software centre is a nice addition and I think this will help a lot of new users find what they are looking for but could do with some expansion on the search criteria.
In terms of day to day use it's pretty good thought! Libre Office works in it's usual seamless manner as well as most other productive software... I did have issues with WireShark picking up the right interface though.
My personal preference was to change the browser to Chromium and the music player to Amarok (especially if you use Lastfm's Scrobble feature). I'd probably recommend the novice user still steer clear for a little while longer (at least from unity anyway) but overall its a step in the right direction, it's nice to see some major development on a GUI for once.