I just ran across this nice video that was done by the World of GNOME team:

It does a great job of highlighting some of the new things in 3.8. Worth watching, if you don’t want to wait until GNOME 3.8 appears in stable distributions, such as Fedora 19 (in ~ 2 months).

There is a silent version of the video as well, if you have trouble viewing the one above.