Muglia "has done a very credible job" leading the server division, DiDio continues. But "Ballmer wants to take it to the next level where they are seen as a real player in the cloud. There's a lot of flux going on right now at Microsoft. I would not be surprised to see a lot more people leave."

Whether Muglia was given the opportunity to stay on at Microsoft in a different role was not discussed in Ballmer's email. Muglia was a Microsoft employee for 23 years, and previously led the Developer, Office and Mobile Devices divisions. Once Ballmer decided to replace him in Server and Tools, Muglia probably didn't see much point in sticking around, analysts say.

"There may simply be no other place for him to go," King says. "When you're a division head at a company like Microsoft, the next logical step would be in the C-level executive sphere."

in Network World's Software section.