It contains two new "generic" fixes and a few that are focused on Office Communicator 2007 interop issues -
936351 - The conversation history is cluttered and is difficult to read in Communicator 2005 when Communicator 2007 is used to initiate a conversation and when Multiparty IM is used
934581 - You see a black screen or a still video image after a video works briefly in Communicator 2005
935868 - Information for users is incorrectly displayed in Office Communicator 2005
936352 - A Communicator 2007 user cannot add a video to an audio call that is between a Communicator 2007 client and a Communicator 2005 client
I just installed it - but this will be the last one as we are migrating all of our internal users to OCS 2007 B3R in the coming days (As part of one of our customers OCS Voice TAP's we need to move along with our own installation).
Find the hotfix download here