When you have phones syncing to SBS 2003 and you move to SBS 2008, and you move the Godaddy cert from the one server to the other and thus do not need to deploy any new SSL certs…. the iPhones typically just need a powering off and powering back on.
For Windows Mobile, however, they need to accept the SBS mobile policy.
Now you may want to tweak this policy to turn off the requirement of a PIN password on the phones.
Go into the Exchange management, then org, then client access and adjust the Exchange activesync mailbox policies (or set up a new one) as your organization deems fit.