BlackBerry Enterprise Server for Microsoft Exchange Version: 5.0 | Service Pack: 1

Interesting .. http://docs.blackberry.com/en/admin/deliverables/12039/BlackBerry_Enterprise_Server_for_Microsoft_Exchange-Release_Notes–934496-1104102201-001-5.0.1-US.pdf

Hightlight for me is: Support for Microsoft Exchange Web Services.  You can configure the BlackBerry Enterprise Server to use Microsoft Exchange Web Services instead of MAPI and CDO libraries to manage calendars on BlackBerry devices. You configure support for Microsoft Exchange Web Services using the BlackBerry Enterprise Trait Tool. To configure the BlackBerry Enterprise Server to use Microsoft Exchange Web Services, your organization’s environment must use Microsoft Exchange 2007 SP1 or later.