Just looking around at some more details around the forthcoming Exchange SP2 release and it's additional functionality relating to security from the MS Exchange Team themselves:
Exchange 2003 Service Pack 2 (SP2) Remote Wipe functionality
Enforcing security settings on mobile devices with Exchange 2003 SP2
Of particular note is this rather nice, almost historical, recap on the way ActiveSync across the wire has developed:
Solving the Phone Synchronization Problem End-to-End
Along with this I also came across some details from the MS Mobile 5 Team regarding exactly what changes are in Mobile 5 with regard to the change to Persistent Storage.
http://blogs.msdn.com/windowsmobile/archive/2005/07/14/438991.aspx
http://blogs.msdn.com/windowsmobile/archive/2005/07/18/440092.aspx
http://blogs.msdn.com/windowsmobile/archive/2005/07/18/440139.aspx
I appreciate it's 3 seperate articles, but quite illuminating and worth the effort, but if you really can't be bothered?
;-) then get ready, the change to Persistent Storage will have a dramatic effect in future battery life.