When you are the chief of a big company do you jettison a man who has just been in charge of launching an operating system on which you are betting the whole company? Is that his reward?
Is this a message to the world at large – confirming an opinion which some tech pundits have advanced – that the top brass at Microsoft feel that Windows 8 is going to be another disaster?
Or is this chief executive Steve Ballmer's survival instinct at work? Sinofsky, 47, (above) would have been one of the people in line for the top job, given that he brought order to the company after the Vista debacle.
That Windows 7 was released to generally positive reviews was all due to Sinofsky. He became vice-president of the Windows and Windows Live divisions in 2006, as the Vista disaster was grinding to an end.
A product was needed and needed fast. Vista has been called, for good reason, the tech disaster of the decade. Sinofsky saved the company's bacon with Windows 7.
In 2009, he was promoted as president of both divisions. In every presentation of Windows 8 to the world of developers, his face has been seen.
A degree of the regard in which Sinofsky was held is the fact that he was given the role of technical assistant to Bill Gates in 1992, just three years after he joined the company.
Ballmer's presence in the company is solely because he is a buddy of Gates. While Gates was part of the company hierarchy, there was a technical head to guide things and cover for Ballmer's lack of knowledge on this front.
But in the first decade of the new century, under Ballmer, Microsoft has fallen behind in every sector that counts. Music, mobile, tablets - Windows is not even a mention in any of these spaces. Windows 8 is Ballmer's last chance to prove he is of some worth.
Ballmer was probably stuck between keeping Sinofsky within the fold and outflanking every move he made towards the top job, or getting rid of him and saving his own backside.
The promotion of a woman, Julie-Larson-Green, to take over from Sinofsky goes against character: Microsoft has never been known to be overly friendly to women ascending to the senior ranks. Ida Cole and Jean Richardson are probably the only two to have made it to vice-presidential ranks in the company.
But these days that kind of attitude doesn't boil; the days of the caveman are over. Microsoft is now a company that is involved with The Ada Initiative, a project to increase the number of women in technology. The promotion of Larson-Green plays well to the kind of image the company would like to have.
It won't take very long for the world at large to find out if Ballmer's head is on the chopping block or not. At the latest by the end of 2013, Microsoft will have to either announce his successor, or else publicly renew its confidence in his leadership.