Exchange 2007 Service Pack 1
Yep, available now.
Improvements in Exchange Server 2007 SP1 include:
Anywhere Access
• Integrated Exchange Unified Messaging functionality with Microsoft Office Communicator 2007 and Microsoft Office Communications Server 2007.
• Outlook Web Access additions, including public folder access, S/MIME support, personal distribution lists, and mailbox rules editor.
• Webready document viewer supports Microsoft Office 2007 documents in addition to Microsoft Office 2003 documents.
• Extended language support in Outlook Web Access with Arabic and Korean spell checking.
Operational Efficiency
• Support for Windows Server 2008 deployments, including benefits in flexible clustering, native virtualization, advanced networking, and simplified management.
• Additional tools in the Exchange Management Console, including public folder management and configuration options for clustering and POP/IMAP access.
• Improvements to the Exchange Management Shell syntax and import-export PST in the move-mailbox command.
• Wider variety of web services for application development, including public folder access, delegate management, and folder level permissions.
Built-in Protection
• Addition of Standby Continuous Replication (SCR) for site resilient high availability deployments.
• Extended Exchange ActiveSync policies for mobile policy enforcement.
• Information rights management pre-licensing by the Hub Transport role.
• Secure Real Time Protocol (SRTP) support in the Unified Messaging role.
• Support for IPv6 when using Windows Server 2008.