With Windows Live Messenger barely out the door, Martin Taylor, Microsoft's corporate vice president of Windows Live and MSN, has unexpectedly left the company. Taylor was appointed to lead the Windows Live marketing effort in March 2006. He had been with Microsoft for 13 years.

What's mysterious is that neither Taylor nor Microsoft has explained the departure. "We have made the difficult decision to part ways with Martin, but we don't comment on personnel matters," a Microsoft representative said. "We appreciate Martin's contributions at Microsoft over the past 13 years." That's the kind of send-off the Soviets used to give recently deceased party chairmen, and the announcement reads as if it's meant to provoke questions.

Speculation is that recently appointed Chief Software Architect Ray Ozzie--who pushed Microsoft into creating its Windows Live and Office Live services last year--wants to put his own team of people in place around him. Interestingly enough, Taylor was a protégé of Microsoft CEO Steve Ballmer and worked with Ballmer for several years to devise Microsoft's long-term product strategy.

In related news, Ted Hase, one of the four original Xbox team members and co-creator of Windows XP Media Center Edition, has also left Microsoft. Hase hasn't revealed why he left the company or what he plans to do next, stating only that "it's time for a change." Hase was at Microsoft for 16 years.