Exchange 2010 SP1 released...
Microsoft Exchange Server 2010 Service Pack 1 (SP1)
Microsoft Exchange Server 2010 helps you achieve new levels of reliability and performance by delivering features that help to simplify your administration, protect your communications, and delight your customers by meeting their demands for greater business mobility.
Microsoft Exchange Server 2010 SP1 RTM Protocol Documentation
• Supported Operating Systems: Windows 7 Professional 64-bit; Windows Server 2008; Windows Server 2008 Enterprise; Windows Server 2008 R2 Enterprise; Windows Server 2008 R2 Standard; Windows Vista 64-bit Editions Service Pack 1
Exchange Server 2010 SP1 System Requirements and Prerequisites
This SP1 software may be used to both update an existing Exchange 2010 installation to Service Pack 1 (SP1) and perform new installations.
For information about Exchange 2010 system requirements and prerequisites, see the following topics:
• Exchange 2010 System Requirements
• Exchange 2010 Prerequisites
Actual requirements will vary based on system configuration and specific features installed. For more detailed system requirements, please refer to the Exchange Server 2010 Technical Documentation Library.
For a list of Windows Server 2008 requirements, visit http://technet.microsoft.com/windowsserver/2008.