Microsoft has already shown a version of Office running on ARM natively. For lot of current Windows app written in .NET or standard Windows API, the transition

Microsoft has already shown a version of Office running on ARM natively. For lot of current Windows app written in .NET or standard Windows API, the transition should be easy so long as MS maintains the same API's across architecture. Only problem would be for old legacy software where company that maintained it is out of business, or software that heavily relies on kernel specific functionality, etc