If you enabled the gnome3-team ppa for Raring, you'll notice that your laptop won't suspend anymore when you close the lid. That is...
I had some trouble getting gnome-boxes to work on my Ubuntu machine. It turned out to be due to having an encrypted home directory, see...
I installed gnome 3.6 in ubuntu from ricotz' staging and testing ppa's. My experience wasn't very stable though (sound not working...