Active Directory Extensions to go?
There is a strong possibility that the Active Directory User Extensions will go. In exchange 2003 you could manage the exchange bits of a user either by running Active Directory Users and Computers on the Exchange server or by installing the Exchange extensions onto a DC. Although the ADUC extensions are still there in Beta 1 it sounds like they will be dropped in later releases. This explains why the proxy address creation didn’t work earlier. Users will be mail enabled using recipient policies in the Exchange Manager tool.
There seems to be quite a bit of reistance to this idea of thinking already.