jcombel writes "It turns out Microsoft's app compatibility will be limited to one architecture or another. Yes, Windows 8 will run on your ARM tablet, but your x86 Office 2003 will not. In his explanation, Steven Sinofsky reasoned, 'If we allow the world of x86 application support like that, or based on what we call desktop apps in our start yesterday, then there are real challenges in some of the value propositions for system on a chip,' he said. 'You know, will battery life be as good, for example? Well, those applications aren't written to be really great in the face of limited battery constraints, which is a value proposition of the Metro style apps.'"