I want to thank Nathan Winters for this gem, there's now a Excange 2003 System Manager for Vista you can download from Microsoft.
I fault the 3rd party hardware and software manufacturers with the many compatibility issues that have plagued Vista, when they had a FIVE YEAR window for development (HP Photo printer anyone?), but to have Microsoft come late to the party with Windows server and Exchange management tools is just lame. Do they want the MS tech crowd on their side or not?
In any case, better late than never.