Found this good read. http://blogs.technet.com/b/dodeitte/archive/2010/10/20/what-happens-during-schemaprep-in-lync-server-2010.aspx
Major updates include App-V 4.6 SP1 http://blogs.technet.com/b/appv/archive/2011/03/10/mdop-2011-including-app-v-4-6-sp1-is-now-available.aspx