One of the nicest features of my iPhone remains the mail sync capabilities. I’m a heavy email user and sync several accounts which include MobileMe and Exchange. This unfortunately means I also have first-hand experience of just how hard that hits the puny 3G battery 
roll on the iPhone released next summer!
Anyhow, Apple aren’t known for their openness when it comes to disclosing the finer points of their updates, so it’s no suprise there are some undocumented changes in iPhone 3.1 which are causing a range of pains for iPhone/3G/3GS users.
It turns out that until 3.1, the implementation of Exchange ActiveSync in 3.1 was fairly weak from a security perspective. Organisations which are using Exchange 2007 and have device policies set couldn’t properly block handsets which didn’t have a pin code set or encryption enabled.
So for users of the original iPhone and 3G as of 3.1 if your firm uses such policies you’re stuck between a rock and a hard place – unless they relax the Exchange ActiveSync policy associated with your exchange account (preferrably creating a new policy which is applied specifically to those with affected devices) your syncing days are over.
Users with the 3GS will either be prompted to use a PIN (or error out if one isn’t used, I don’t recall which) and find that encryption is enforced (if policy dictates).
Of course this is really an internal IS problem, after all nobody would connect their personal telephone to the corporate messaging infrastructure, right? 
