According to John Fontana, Networkworld.com (http://www.networkworld.com/news/2006/061606-exchange-2007.html )
"Corporate users who migrate to Exchange 2007 (yes, no upgrades!) will face mandatory infrastructure changes that, while advancing security and management could add complexity and costs to their networks"!
According to the article, you will need to deal with the following:
- Requires 64bit processors - so you have to buy new hardware.
- The new role based architecture may require upto 5 exchange servers to support remote client access, transport/routing, unified messaging, and mailboxes.
- New clustering limitations - move from server consolidation thought to server expansion, given the increase in # of servers required.
- Eliminate all Exchange 5.5 servers from the environment!
- No in place upgrades from Exchange 2000/2003 to 2007.
- Exchange no longer will have its own site topology.
- Integrate Exchange with a PBX - specs not available yet.
- Need compatibility kits for third party 32bit plugins that may not run on Exchange 2007
I expect Microsoft will soon release the following:
- detailed migration and best practice guidelines for users
- public beta of Exchange in July 2006
- licensing options requirements for Exchange 2007
So, why wait?
Move to Domino or DAMO (for Outlook fans), run it on Linux, to help save some money so you can invest it in other mission critical initiatives!