The OC 2007 R2 Evaluation Edition is now [re]-released. KB article 980093 pertains to this release of OC.

Description of the update for the Evaluation version of Office Communicator 2007 R2: February 2010

http://support.microsoft.com/default.aspx?scid=kb;EN-US;980093

The Evaluation MSI is available at the following link.

http://www.microsoft.com/downloads/details.aspx?FamilyID=535637af-d92f-41b1-bf0c-54a526a88247