Compelling argument by Charlie Demerjian at SemiAccurate that Microsoft has already entered its death spiral:
The problem is that if you are locked in with a choice of 100% Microsoft or 0% Microsoft, once someone goes, it isn’t a baby step, they are gone. Once you start using Google Docs and the related suites, you have no need for Office. That means you, or likely your company, saves several hundred dollars a head. No need for Office means no need for Exchange. No need for Exchange means no need for Windows Server. No need for Office means no need for Windows. Once the snowball starts rolling, it picks up speed at a frightening pace. And that is where we are. The barriers to exit are now even more potent barriers to entry.