Exchange devs and IT Pros: here's that SP1 you've been waiting for. This release contains support for Windows Server 2008, improved integration with Office Communications Server 2007, and better mobile device security and management. Also, there's more functionality for the Exchange Managment Console and improved disaster recovery through Standby Continous Replication. 

For deployment details see http://www.microsoft.com/exchange

The final release of Forefront Security for Exchange 2007 SP1 is also available: http://www.microsoft.com/forefront/downloads.mspx