We received a lot of questions about, and requests for, support for Lync 2010 Windows desktop client in a Lync hybrid deployment. After a round of testing, we are happy to announce that the Lync 2010 Windows desktop client is now officially supported for Lync users in a hybrid deployment, including users that are homed in Lync Online through an Office 365 tenant.
Special thanks to Dave Howe, Sr. Support Escalation Engineer, for making this happen!
The Lync 2010 desktop client must be version 4.0.7577.4419 (or later) released in January 2014, as described here: http://support.microsoft.com/kb/2912208.
About Lync Server hybrid
For more information about hybrid deployments, see: