My probability of that happening in the consumer space is fairly low unless Windows8 comes to be able to run snappily on tablets whose exterior does not get hot to the touch. (The exterior of the iPad never gets hot to the touch.) And my probability that MS (and Intel) will achieve that is fairly low because my probability is fairly low that MS and Intel (considered a single entity cooperating to expand into the consumer tablet market) will come to understand and take the "heat factor" sufficiently seriously.
But IMHO even if Windows8 tablets (as I expect) will get hot to the touch, Windows8 tablets will probably eventually succeed in mostly expelling the iPad from the enterprise (because employees have much less freedom to choose their hardware than consumers do and will tend much more strongly to put up with hot external surfaces).
Not quite true. MS went pretty deep in Itanium. The platform didn't sell and they eventually gave up, but they committed a fair bit to it.
MS has also long supported ARM with Windows CE. And there was a project called LongARM where MS ported Vista(?) to ARM. Also recall MS did SPOT watches and robotics among other random things. And in their biggest non-x86 move they did XBox360 using IBM processors.
And now Microsoft, once an unstoppable juggernaut, just doesn't get it when Ballmer describes tablets as "just another form factor". They failed for 10 years to make tablets just another way to sell more Windows licenses. They're still kicking that dead horse with Windows 8.
I think its a mistake to say that a "strategy" that failed 10 years ago won't work now. Apple's strategy of building the full HW/SW stack also failed in the past, but its working now. Timing and execution are both important. More than Android, I think Windows8 will be the big iPad tablet competitor.