The Exchange Connector 3.0 for Service Manager has been re-released today. It includes the Bug Fix for the issue related to extending the work item classes data model with custom properties. A link about that issue is here:
This is great as you no longer have to open a support case with Microsoft to get the fix. The new Exchange Connector 3.0 can be downloaded here:
http://www.microsoft.com/en-us/download/details.aspx?id=38791
