So, you might ask, what's new? iCloud and Windows 8 aren't new revelations, after all. What's new is that Windows 8 may not be the awkwardly bifurcated platform it first appeared to be, with a "full" Windows 8 (meaning the Windows 7 desktop and the touch-oriented Metro UI overlay) on x86-based PCs, laptops, and perhaps tablets, while a mobile-oriented "lite" Windows 8 (meaning just Metro) lives on ARM-based tablets and perhaps laptops and PCs. That split clearly favored the x86 PC.
What Microsoft has shown of Metro so far is not that compelling: It's a lighter-weight OS than Apple's iOS or Google's Android, translated into weakly useful widgets in Microsoft's demos. Likewise, the ARM world that one could envision from Microsoft's drips of information was not particularly inspiring, appearing more as a warning shot to Intel to get its power act together.
Apple explicitly read Intel the riot act about its power-hogging chips as well, going as far as demonstrating a port of Mac OS X from x86 to ARM to show that it could drop Intel. After all, the iPad's ARM-based iOS comes from the same core as Mac OS X. The results of that pressure are the new Intel Atom CPUs soon to appear in mobile devices and a revamped Core i5 chip family due next year that promises iPad- and MacBook Air-like battery life without the major efforts that Apple had to make to get the MacBook Air's long battery life.
With ARM devices restricted to a lightweight Metro UI and Intel fixing its errant ways, it seemed obvious that an ARM-based Windows 8 tablet or laptop would be not much more useful than a Google Chrome OS-based Chromebook, primarily a browser-oriented device -- and one that has failed spectacularly among buyers.
Decoupling Office from x86 is pivotal
But if Microsoft can truly port Office -- the complex desktop version, not the useless iteration available on Windows Phone 7 -- then Windows 8 on ARM could become most users' PC. The Windows 7 core underlying Windows 8 has been the essential component to support Office, and most people use PCs to just run a browser, do email, manage their contacts and calendar, and work with Office. The first three can be accomplished with an iPad or Android tablet today, as well as with the Windows 8 Metro environment. Office was the one component that would keep most users on the x86 version.
With Office no longer tied to the x86 version of Windows, most people could get an ARM-based tablet or laptop. I suspect most will, even if not in the first few months. The iPad's roaring success shows people don't need a bulky OS most of the time. Yes, some people will need "full" PCs (or Macs, in some cases) to run heavy apps -- financial analysts, video editors, core ERP users, and the like. For them, the x86-based PC (or Mac) will be the new workstation, used by perhaps 10 percent of the computing population. The rest don't need it, and for the few times they may, the well-established desktop virtualization technology could let them access a workstation PC from a tablet or "lite" laptop.
Plus, based on the video snippets Sinofsky showed of the ARM-based Office, it lacks the ribbon interface. Microsoft's traditional Windows and Office interfaces have grown more complex and inscrutable over time. (Microsoft always claims it conducts extensive user interface research, but still revamps the UI every chance it gets. It must be using a different species of alien each time.) In a touch-oriented environment, rows and rows of small, undeciperhable icons just don't work. Someone at Microsoft seems to have realized that, and perhaps Office for ARM will be truly usable. That alone could move many users away from the "heavy" x86 version of Office and, thus, Windows.
Of course, Microsoft's promises don't matter if it doesn't deliver. What Sinofsky described as a highly capable version of Office could be crippled in its capabilities. He made no specific functionality promises and added the caveats that Office for ARM-based Windows would be optimized for touch and low-power systems, two excuses that could be used to explain missing capabilities in the final shipping version.
Microsoft has done this before. Ask any Mac user: Office for Mac lacks key Windows Office capabilities -- such as the ability to integrate with the Office 365 cloud service, to integrate with SharePoint, and to use Visual Basic macros -- because Microsoft withheld those technologies from the Mac deployment.