Quick update, the MCX package is now available from Microsoft. These bits along with CU4 allow you to turn on Lync mobile client functionality. The client bits will be available on the appstores/mareketplaces for the phone some time before the end of the year, but I have no inside information on when.
Before deploying the new bits or CU4 in production make sure to test in your lab, read the documentation and update your load balancer configurations (links below). If time allows and someone else doesn’t beat me to it, I’ll publish an article on the mobility configuration shortly.
Mobility and Autodiscover Services: http://www.microsoft.com/download/en/details.aspx?id=28356
Mobility Deployment Guide: http://www.microsoft.com/download/en/details.aspx?id=28355
Hardware Load Balancer Requirements for Lync 2010 (Updated for CU4): http://blogs.technet.com/b/nexthop/archive/2011/11/03/hardware-load-balancer-requirements-for-lync-server-2010.aspx