Microsoft Exchange 2007 represents a major decision point for organizations that are using Exchange 2003 or earlier, as well as for organizations that are on other platforms and that are considering hopping onto the Microsoft roadmap.

The decision to migrate to Exchange 2007 is not a trivial one. An organization that needs high availability with Exchange through clustering will need a minimum of four servers, not counting the new unified communications capabilities available with Exchange. While Exchange Server and Client Access License (CAL) pricing remains unchanged from Exchange 2003, Outlook 2007 is now an additional $105 per user instead of being included in the CAL as with past versions. Exchange 2007 requires 64-bit hardware, meaning that the server hardware you purchased before Q3/2005 is unlikely to work with Exchange 2007.

That said, the benefits of Exchange 2007 are substantial. Server loading is now more than double what it was in Exchange 2003, allowing much greater server consolidation and potentially lower costs of management. Security, compliance, mobility, Web access to e-mail and encryption are significantly improved. Plus, Exchange 2007 represents a paradigm shift in the context of unified messaging by integrating voicemail and fax into the user’s mailbox.

Our research shows that there will be a substantial migration to Exchange 2007 during the course of this year, but not a stampede. Certainly, the migration to 64-bit hardware and other issues may slow adoption of Exchange among many potential customers, but I believe that the most significant issue is that Exchange 2007 represents a move to unified communications – that shift in thinking about communications, more than just the migration to a new messaging system, is what is probably giving people pause as they consider the move.

I’d like to get your thoughts if you’re using any version of Exchange right now or are considering a migration to Exchange 2007. What is holding you back from making the move right now? Cost? Unified communications? Please send me an e-mail with your thoughts.

Michael Osterman is principal analyst of Osterman Research.