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.
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:
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.
Checkout the MSExchangeTeam Blog for information on the new features and functionality that has been introduced in Service Pack 1.