One of the things about working odd hours is I see things come in from the US, when most sensible Brits are in bed. One came with the message

"This announcement was originally scheduled to happen Thursday, August 30th, 2007 at 7AM PDT- however CNET broke embargo  http://news.com.com/Microsoft+to+buy+corporate+group+chat+company/2110-1014_3-6205224.html?tag=item "

We are announcing our  intent to acquire Chicago-based Parlano, makers of the MindAlign group chat application. The deal is expected to be complete in the fourth quarter of 2007. Microsoft expects to incorporate Parlano’s group chat technology into Office Communications Server and Office Communicator,  and plans to offer group chat as part of the standard client access license for Office Communications Server 2007 Software Assurance customers. Microsoft believes this acquisition will strengthen the current unified communications offerings, particularly in financial services.

I'll admit that the I've never missed the kind of Persistent chat that Parlano offers, but having dealt with quite a mix of clients I know there are a good number of organizations out there who view it as absolutely essential. Everyone seemed to think Parlano had the best product in this niche, so reading between the lines it seemed like the folks who decide these things thought the best way to round out the product was to buy them.