Microsoft officials announced on October 8 that Exchange Server 2010 is done and has been released to manufacturing.
From the Microsoft Exchange Team Blog:
"We are happy to announce that Exchange 2010 is Code Complete! Our senior leadership team has signed off on the final code, and it has been sent to our early adopters for one final look before its public release. This Release to Manufacturing (RTM) milestone means we are on our way to general availability and the launch at Tech·Ed Europe 2009 (http://www.microsoft.com/europe/teched/) in early November."
Microsoft released a near-final Release Candidate (RC) test build of Exchange 2010 in August. As many as 1 million testers have been test-driving the public beta version of Microsoft’s on-premise Exchange Server 2010 product since April of this year. Another 5 million or so testers have been working with the cloud-based complement in the form of Outlook Live, which is a slightly modified version of the Exchange Online product.
Exchange 2010 is a 64-bit-only release. The product includes new, integrated e-mail archive functionality; the ability to see text previews of voice mail; a new “Conversation View” feature; customizable call-routing menus; and a “MailTips” feature designed to help stamp out e-mail “faux pas.” It also includes a newly renamed version of Outlook Web Access (now known as Outlook Web App) that works with a variety of browsers.
Update: Microsoft is not planning to post the RTM bits for Exchange 2010 to TechNet or MSDN early. A spokesperson told me the bits won't be available to any users until the November TechEd Europe launch.