Not strictly a Group Policy video but it does relate heavy to my Roaming Profiles and Folder Redirection (a.k.a. User State Virtualization) blog post.
Anjli is a program manager on the Windows team. Adam Bomb met with her recently to talk about offline folders and folder redirection in Windows. She talked about how the technologies work, when they should be used, and some of the ways we’ve improved the performance from previous releases. for more info, check out the whitepaper "Choosing an Appropriate User State Virtualization Solution" The Windows team blog also has some good posts on User State Virtualization here and here.
For more video goodness, there’s a 3 part series on user state scenarios located here.