Microsoft is betting that buyers will like the fact that one device can do both without the need for remote desktop applications. Splitting up the OS would eliminate that advantage.
The last possibility, and the one I think most likely, would be for Microsoft to continue to evolve Windows.
The new interface would become more powerful and useful, while gradually chipping away at all the reasons you might need to revert to the desktop. Slowly, the benefits that the new interface provides-things like universal search, app-to-app sharing, and built-in cloud storage-would overshadow its drawbacks.
Even if Windows 8 bombs, Microsoft won't give up. When Redmond wants in on an important market, it tends to keep throwing money and resources at it. We saw that with Bing, we saw it with Windows Phone, and we're going to see it again with Windows 8.
Time will tell if Microsoft can be more successful with Windows 8 than those other efforts. Either way, it's highly unlikely that Microsoft will abandon its current vision and let this new wave of computing pass the company by. Desktop purists may not like the new look of Windows, but it's here to stay.
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