I was able to publish an article on the topic of support for Service Packs on the Next Hop blog. I have a few edits requested but do let me know if there is anything unclear or worse conflicting with existing documentation.

http://blogs.technet.com/b/nexthop/archive/2011/02/24/support-for-service-pack-updates-in-lync-server-2010-and-office-communications-server.aspx

TomL LCSKid