Originally Posted by al_bundy
at some point i the next 1-3 years the size of iOS and WinARM will be about the same along with hardware requirements
That seems pretty unlikely. Windows7 compiled to run on ARM is still Windows. iOS is first and foremost a mobile touch screen operating system, and added functionality still doesn't bring all the legacy cruft of Windows.
Now if MS wants to take their ARM version and start radically reworking it to create a mobile touch specific version, then sure-- I could see iOS and such an animal having similar footprints and hardware requirements (although Apple seems to be more focused on efficiency and power optimization than the competition, so there would probably always be a gap). But that would be because Windows Mobile Edition or whatever had gotten more compact, not because iOS had gotten bigger and less efficient.
And, anyway, none of that is likely to happen because MS already has a touch based mobile OS in the form of Windows Phone 7, based on the separate CE OS. It would seem pointless for MS to start trying to drive Windows per se into CE territory, hardware requirement wise, instead of trying to expand the capacities of CE.
Of course this a problem that Apple will never have-- as hardware gets more capable, they can steadily add OS X features until the two OS versions are on par, with the only difference being the UI.