I'm leaving it up to the MVP's to blog about all the cool features in 2010 but will share some tips on ways to do things in a production environment that developers or "as-built" IT people always seem to do through the 20 click UI procedure.
One such example is that the account running the User Profile Synchronization service must have "Replicating Directory Changes" permission on the domain, even if you only want to do full imports.
You can do this with the Active Directory Users and Computers UI or with the command line:
dsacls DC=Contoso,DC=Com /G "Contoso\svcProfSync:CA;Replicating Directory Changes"
I place commands like in a server prep cmd file which, among other things, creates my service accounts, adds all the roles and features required for SharePoint installation, changes IIS settings etc...