Find them all at http://edge.technet.com/Tags/Hyper-V/
2 new ones to check out:
Windows XP Mode for Windows 7 on TechNet Edge
7 minutes, 25 seconds The announcement of Windows XP mode caused a lot of excitement. In this screencast we have a look at how it is set up, what users see, and get an idea of what it can do. Windows XP Mode for Windows 7 makes it easy to install and run many of your Windows XP productivity applications directly on a Windows 7-based PC. Download Windows XP Mode Beta.
TechNet Edge: Dual Boot from VHD with Windows 7 and Windows Sever 2008 R2
23 minutes, 0 seconds Want to learn how to boot from VHD with the new operating systems we have coming? How about dual boot with Windows 7 and Windows Server 2008 R2?