We've published many videos of the upcoming GNOME Shell, but none of the classic GNOME 3. Here's a video demoing the latest GNOME 3 beta 2 (without GNOME Shell) running in VirtualBox:
In the video you can notice the new Gnome Control Center, Nautilus 3 beta 2 and so on as well as the new Adwaita theme. The video wasn't recorded by me and the person who created it seems a bit in a hurry so you won't see all the new stuff in Gnome 3, but it should be enough to get an idea of how it looks like.
Thanks to OSSBlog.it for the news!