Mirror ports and stable or cvsup
The main idea is to work on defined revisions.
Many people will install server A) on 8.1-RC2, server B) on 8.1 server C) on -stable
Instead install all of them using 8-Stable-2011-03-25 and build their ports using that etc.
If you need a security patch, use revision from 2011-04-20 and rebuild it. then install on all systems.
If a system doesn't have a downtime now, then so be it. once it has the downtime, install the patch that all the others got, instead of updating ports and ... ...
...a certain point of -stable and deploy that. only your patch testing systems should track stable (i.e. rebuild once per week)