Microsoft and everybody else has been waiting for years for Intel to reduce the power consumption of x86, so long that ARM has caught up from an CPU appropriate for mobile devices to an serious competitor to the dominant platform.
Intel has done everything they can to "prove" that their chips are ready, but they've done the same thing before. They partnered with Nokia and rebuilt their system for internet tablets into a general purpose system for mobile devices (including netbooks), then automotive systems. They released a chip for smart TVs and set-top boxes, then abandoned the entire line, leaving devices without firmware updates in certain devices (like Boxee). They've gone to great lengths to target smartphones and smaller tablets where the larger footprint would be a serious downside.
I will admit that intel has finally delivered a chip that is competitive with ARM on smartphones and smaller tablets.
I will agree with another commenter (either here or on the other story) that it is too early for the RT to be introduced as a product category. But I also believe that Microsoft has to succeed in getting a Windows product on ARM based on the NT kernel if they want to maintain their long-term dominance in personal computing, particularly for businesses.
They may have the wrong idea with trying to build a media consumption tablet built around applications in the same device as they have with Windows RT. I would suggest they take the opportunity with the 8.1 upgrade to support arbitrary compiled Windows applications, starting with Google Chrome and Mozilla Firefox. (Both would likely be ported if that was possible.) That they embrace developers using Visual Studio 2012 to build applications on the device, not just for the device. I would suggest that they use Microsoft Installer (MSI) to hide the fact that the applications are compiled for ARM, call them "Universal Windows Applications" if they must.
I considered the Surface RT before getting my Samsung Chromebook (ARM) and went for the latter of both price and lack of support for Windows (Win32) applications on the RT.