I have a user who would like to access another persons Outlook 2007 calendar instead of his own. He already has permissions on the calendar via outlook.
Outlook 2007
Exchange 2000
BES 4.1.3.18
BB model 8830
He syncs over the air, no direct connect to desktop.
There is a software from diditbetter.com - even, if not cheap, it does something similar and works fine.
It synchronizes exchange private or public folders against another folder.
You still will have only one calendar on the device, but the contents will be synchronized with another user/public calendar.