On the management side, OCS has chunky new features as well. Federated identity management, for example, is handled from inside OCS, as are most day-to-day management duties, and the server supposedly has a good auditing system, too. System Center extensions are in the works, but a real nice integration is that of OCS and SharePoint, where higher-level users can utilize OCS functions as part of Office SharePoint workflow designs.
OCS has many more nifty features that we'll explore in an upcoming Office Server review: Live Meeting, conferencing, tablet support, a full-on Web client, and more. Meanwhile, solving the Great Mystery of OCS 2007 is simply about realizing that it's trying to become a network communications hub behind the firewall. Whether it's IM, shared meetings, or VoIP, it's all there, which really isn't anything new these days. But the way in which it integrates with Office 2007 and the other Office Server platforms, that's where OCS might really stand apart.