Here are some of the technical videos on exchange and lync servers which took place @ TechEd, North America 2013, New Orleans.

Monitoring Microsoft Lync Server 2013: Getting the Most out of Monitoring Service Data
Designing for High Availability and Disaster Recovery in Microsoft Lync Server 2013
Microsoft Exchange Server 2013 Managed Availability
Microsoft Exchange Server 2013 Client Access Server Role
Migration and Coexistence with Microsoft Lync Server 2013
Microsoft Exchange Server 2013 High Availability and Site Resilience
Microsoft Exchange Server 2013 On-Premises Upgrade and Coexistence
Enterprise Network Requirements for Microsoft Lync Server 2013
Microsoft Exchange Server 2013 Sizing
Planning and Deploying Your Enterprise Voice
Planning and Deploying Your Enterprise Voice
Deep Dive into New Unified Communications Web API of Lync 2013
Data Loss Prevention in Microsoft Exchange and Microsoft Outlook 2013
Team Collaboration with Site Mailboxes
Microsoft Exchange Archiving Policy: Move, Delete, or Hold
Planning and Deployment for Edge Server with Microsoft Lync Server 2013
The Deep Dark Secrets of Unified Messaging
Microsoft Lync Server 2013 Dial Plan and Voice Routing Deep Dive
All about Archiving with Microsoft Lync Server 2013
The New Outlook Web App: Designed for Touch and Offline Too!
Scripting and Automation for Microsoft Lync
Introducing Lync Room System

Cheers,