It's something only mentioned in passing in the ShoreTel press release and completely glossed over in the What's New in ShoreTel 8.1 blog. But here's a bit on how it works. ShoreTel customers cannot actually use Microsoft Office Communicator, the LCS/OCS client. Instead, ShoreTel's Personal Call Manager client is deployed to end users' desktops. IM presence info is then pulled from LCS/OCS, telephony presence is pulled from the ShoreTel voice switches, and both types of presence are aggregated on the Personal Call Manager client. This is similar to a few other OCS integrations out there. So all well and good. But the new 8.1 software provides yet another IM option. ShoreTel's Converged Conferencing server now has integrated instant messaging services built into it. So instead of deploying enterprise IM software from a third party, ShoreTel customers can stick with ShoreTel products and (hopefully) get a cleaner IM-and-telephony solution.