Microsoft: What if they redid an OS from scratch?

What if Microsoft completely rebuilt an operating system from the ground up?  Just hit the reset switch on the past 25 or so years of Windows in the making.  Completely redesign a new operating system from scratch.  This blog over at ZDNet talks about Microsoft’s Singularity project(or dream?). In a nutshell, Microsoft is stuck with the Windows line because everyone and their mother uses Windows. If they created a new OS from scratch imagine the revolt from consumers, small business owners, and corporations alike. But what if they do what Apple did with OSX, included an application such as bootcamp so the new operating system could still run the legacy operating system and applications. Virtualization Technology is maturing every quarter with newer and more efficient processors to handle these types of tasks. So why not?