Ellen Muraskin has a pretty thought-provoking article in her latest eWeek column.  The key question is: will Microsoft be making an entry in the enterprise IP Telephony space with SIP and the newest release of its Live Communication Server (LCS 2005, code-named Vienna)? 

Ellen mentions a piece by Mary Jo Foley in Microsoft Watch (interesting to see more on Istanbul, a client that will be able to empower users to change content between text and voice).  So we have a client able to dynamically switch content, a SIP-based server, presence information... all the elements required to build a comprehensive enterprise SIP-based IP PBX.  Can this become a reality?  Maybe so this time around, although it may not be announced at the upcoming VON show.

Note: Just to throw some wood on the fire: Anoop Gupta, Corporate VP of the Real-Time Collaboration Business Unit at Microsoft is delivering a keynote on Tuesday at 11:15 AM.  Since I am participating at an analyst roundtable happening at the same time, I will not be able to attend Anoop's speech, but look forward to hearing feedback later on during the show.