I'd say no, especially after 23 years... If there is turmoil after 3-4 years on the high profile executive level then it could be because of trouble. But not after 23 years...

From what I gather reading various news sources it looks like the 'silo' management style Sinofsky employs isn't looked at favorably at Microsoft anymore. He probably realized that he isn't able to advance any more in the company and decided to move on. He was being considered as a one of possible Ballmer replacements for the CEO position after Windows 7 launched but that probably wasn't going to happen.

He made something like 17 million dollars in salary and bonuses last year, he can do whatever he wants...

Kowenicki it's huge!  From my understanding he was also a huge control freak. The whole notion of not include a classical menu system was based on his philosophy that Windows 8 should be a clean break.  Many people thought the guy would take over Microsoft from Ballmer.  He's also the reason why J. Allard left Microsoft.

I thought Microsofts decision to go the Windows 8 route and not continue working on the Currier is the reason J. Allard left.

We may never know for sure, but it's pretty unusual for an valuable exec in charge of a very important product to just up and decide to take a break. There's probably drama here somewhere, whether it's ambition, friction with other execs, or Windows 8 market performance.

Larson-Green seems to have had a lot of input into Windows 8, so I suspect that last one isn't it.

The newspaper said that Balmer made him go bc he didn't like the direction Microsoft was taking windows, presumably bc it was too tablet oriented.