I plan to replace our phone system with a Cisco CUCM Business Edition including Unified Presence.
Since the Cisco system integrates well with AD/Exchange services I do not expect to have issues to setup cross authentication etc. as my ZCS does already use AD for authentication.
Still I am unsure what might be feasible with CalDAV/CardDAV or IM to be linked to the CUCM/Presence. Does anyone has an idea or done such a project yet?