Long time Microsoft employee and Microsoft Dynamics CRM community guru Jim Glass announced last week that he has left Microsoft.  Although the terms of the departure are unclear, it sounds like it was a sudden event.  From his farewell blog post:

After 20 years in the military and now 20 years at Microsoft, I am considering how to spend the next 20 years. It's been fun, exciting, and a growing experience here at Microsoft. My last day is Friday 7 October 2011. The company, people, and product groups have treated me very well. Ciao.

And from his twitter account: 

...