The long wait for OCS 2007 is now (nearly) over. During last week, while teaching OCS to British Telecom, I saw that RTM had been achieved at last. Customers on the TAP program can now download the evaluation version of OCS (and Microsoft Office Communicator), and the general customer base should be able to get their hands on the full version by the end of August. The formal launch is scheduled for October.
Microsoft is also working on three official training courses: 5177 (a one-day class covering IM and presence), 5178 (2 days on conferencing) and 5179 (2 days on OCS and Voice). These are meant to be available by launch (although I'm not betting on this!). As the MCT reviewer for these three courses, I'm excited about the content and scope - the courses have the potential to be very good.
You can visit the Microsoft Unified Communications web site (http://www.microsoft.com/uc). For more details on the product and it's features, see the TechNet OCS library Sub-Site (although the landing page does not display well using FireFox). If you are not up to speed with OCS, then a good starting point is the Technical Overview.