Exchange 2003 SP2 is coming :-)
Get a sneak preview of the new features and improvements coming in Service Pack 2 (SP2), scheduled for release in the second half of 2005. SP2 builds on the capabilities of Exchange Server 2003 to offer you even better protection, reliability, easier administration, as well as improved mobile messaging when used in combination with the Microsoft Windows Mobile 5.0 Messaging and Security Feature Pack.
http://www.microsoft.com/exchange/downloads/2003/sp2/overview.mspx