Unrelated to the change, I was awakened at 4am because internet mail had stopped working. First thing I checked was the Forefront services, and found them stopped. Couldn't restart them because the WinHTTP Autodiscover service is disabled.
By the time I got into the office at 7am, reports had started trickling in, complaints that some phones weren't able to connect to Exchange. More investigation revealed a common thread - they were all Android phones. Still have to collect more data, because some Androids are working, while others are not. Shortly after, some Mac clients reported being unable to connect. Seems to be those with older Entourage clients. My own Outlook 2011 client works fine, and supposed the Entourage 2008 client with EWS support will also work. The desktop group is on the job, trying to identify which Macs are having issues, and getting them upgraded.
The phones will be a problem. How do you talk several hundred computer-illiterate people through upgrading their phones to a compatible OS version. And to make matters worse, one of our first upgraded phones still won't connect to 2010 and proxy to a 2007 mailbox. It will connect to either 2007 or 2010 directly, but attempting to proxy from a 2010 CAS to a 2007 mailbox won't work.
Tomorrow I'll pull a report of the ActiveSync client information, in order to identify potential upgrade candidates, so we can come up with a plan to move forward.