This is big and the implications quite serious. What did Kevin see that made him leave? Might it be the tough reality?

In a surprise move, Kevin Johnson, the president of Microsoft's Platforms & Services Division, is leaving the company, Microsoft said this afternoon. Johnson, who reported to Microsoft Chief Executive Steve Ballmer, headed groups including the Windows team and the company's consumer online services, where Microsoft has struggled to keep up with Google in the critical Internet search market.

This isn't an ordinary departure and it's part of an exodus that includes Allchin, Gates, Poole, Valentine, and other key staff.