Check out these Exchange Server 2013 and Lync 2013 videos from TechEd Australia 2012.
Microsoft TechEd NortH America 2012 was held last week and as usual Microsoft is making all the video content available for free online.
In this TechEd session you'll be taken Exchange Server 2010 migrations through some of the important issues and steps along the way.
This video from TechEd Australia 2011 is Scott Schnoll's presentation on Exchange Server 2010 high availability concepts.
This video Lync 2010 meeting features and architecture in Microsoft Lync 2010 Client and Server, for both on-premise and Microsoft Office 365 Service deployments.
In this TechEd Australia 2011 video Microsoft's Ewan MacKellar demonstrates how to troubleshoot one of the most common issues - server performance.
A round up of Microsoft TechEd Australia 2011.