For a list of recent webcasts covering Windows Azure Platform see the following link:
http://www.microsoft.com/events/series/azure.aspx?tab=webcasts&id=odall
No signing in is required to watch these webcasts.
Some Windows Azure AppFabric webcasts from the link above -
Introduction to Windows Azure AppFabric (Level 200) 61 minutes, Aug 2010
Developing for Windows Azure AppFabric Service Bus (Level 300) 53 minutes, Sept 2010
Securing Web Resources Using Windows Azure AppFabric Access Control (Level 300) 55 minutes, Aug 2010
Communication Patterns Supported by Windows Azure Platform AppFabric (Level 200) 60 minutes, Oct 2009