Exchange 2003, formerly known by the code name "Titanium," is the next version in the Exchange messaging and collaboration server line of products. Scheduled to be released in mid-2003, Exchange 2003 will provide many new features and enhancements to improve reliability, manageability, and security. Exchange 2003 will help increase information worker productivity while helping organizations reduce their total cost of ownership (TCO) in areas such as server and site consolidation. In addition, Exchange 2003 is the first version of Exchange designed to run on Windows .NET Server 2003.
You can now order it on CD for free delivery around January in the US here
News source: The inq.