Microsoft (NSDQ:MSFT) is staying mum about the details behindthe sudden departure of Steven Sinofsky, the company’s top Windows executive. Speculation among channel partners and industry analysts centers on reported friction between Sinofsky and other Microsoft executives and questions about the demand for Windows 8 and the availability of applications for the new operating system.

“The timing of Sinofsky’s departure is certainly curious,” said Spencer Ferguson, president and CEO of Wasatch I.T., a Salt Lake City-based Microsoft partner. “I guess it’s better that it happened now instead of before/during the Windows 8 launch.”