Today Microsoft updated their Exchange 2010 Deployment Assistant.It got updated after the initial release in mid-November where you could only select upgrading from Exchange 2003. Now all scenarios work, so you can select if you’re upgrading from Exchange 2003, Exchange 2007, Exchange 2003/2007 or performing a greenfield Exchange 2010 installation.
After selecting the scenario you will be asked a few questions, such as “Are you running a disjounted namespace?” or “Are you planning to to use public folders in Exchange 2010?” (nooooo). When finished you’ll be presented a checklist.
While the tool is available online-only, you can download the checklist for offline use by clicking Download Checklist (top right). This will download the checklist in PDF format. It’s a good reference for planning and can be a useful tool to keep track of where you are in the process.