LCS 2005 Service Pack 1 released.

Live Communications Server 2005 SP1 is now available so you can now use features like federation, Public IM Connectivity (PIC), and support for the new Microsoft Office Communicator 2005 client.  In addition, there is increased security offered with the URL blocking and SPIM filters to help stop the spread if IM worms. 

Live Communications Server 2005 Service Pack 1 (Build 5470) upgrade is available here:

The 120-day Trial Download that contains LCS 2005 with Integrated SP1 is available here:

The release includes:
Live Communications Server 2005 SP1 SE/EE MSDN CDs, VL CDs and the Eval CD (Build 5470)
Live Communications Server 2005 SP1 SE/EE Upgrade web packages (Build 5470)
Live Communications Server 2005 SP1 SE/EE Eval web packages (Build 5470)

SP1 Documentation on Office Online 
Live Communications Server 2005 with Service Pack 1 Planning Guide
Live Communications Server 2005 Address Book Service Planning and Deployment Guide
Updating to Service Pack 1 and Enabling Public IM Connectivity
Live Communications Server 2005 with Service Pack 1 Feature Guide