Stacey over at GigaOM put up Microsoft's press release about R2 today. R2's bringing some much needed feature depth to OCS including better attendant handling, very basic call queueing, dial in audio conferencing and some SIP trunking improvements. However, this isn't the "big one". R2 still misses some very critical components. E911 is still missing. Advanced call queueing and call center type functions are not there. The SIP trunking is still incomplete. And a full OCS implementation just requires too many servers!
The reality of Microsoft's positioning is that a full implementation of the OCS "platform" is too significant an investment for anything but large customers. The Response Point product fills a nice niche in the S of SMB space. Unfortunately there's no upgrade path for Response Point and it really runs out of steam when you get near 50 phones. Microsoft doesn't have a good answer for the M in SMB.
However, R2 does position Microsoft for some very capable trials over the next year, all in anticipation of the next major release due sometime late '09 or early '10. I still believe that will be the real battleground. In a little more than a year Microsoft will truly have a worthy competitor and will start chipping away at Cisco for the Enterprise customers. Perhaps sometime after that they can find a way to roll several roles into a single platform so the Mid-Market has an option too.