Microsoft's marketing exec Michael Sievert just lost his job. The Wall Street Journal reported the news today, but the Windows product marketing VP has probably seen the writing on the wall since February 4. That's when Microsoft CEO Steve Ballmer told analysts Microsoft needs "to be doing more to highlight Windows." It's no wonder. At the end of January, Gartner predicted that by 2011 Apple will have doubled its U.S. and Western Europe computer market share.