The most likely scenario, at least for the short term, is that Microsoft will stand by Windows RT. Whatever the future of Windows may hold, Microsoft clearly believes that failure is not an option. That doesn't mean that the company couldn't sway from its current hybrid user-interface direction. If it stays on the path, though, the cheaper touch-based Windows products become, the stronger the case will be for "Modern" apps that can run on Windows RT.
Then again, Microsoft could just throw in the towel and cancel or postpone further development of Windows RT. At this point, few manufacturers or consumers would miss it. And as Intel-based devices allow for ever-thinner form factors with longer battery life, the case for Windows RT may be even weaker than it is today. Or as an alternative, it could skip a release and wait until enough Modern apps make RT more appealing.
Rather than disappear completely, it is more likely that Microsoft will merge Windows RT with Windows Phone, with which it already shares its kernel. Windows Phone has even less support for legacy desktop applications than RT, but one ARM-based variant that could span both tablets and handsets would align Microsoft's mobile operating system lineup with that of Apple and Google. Consolidation of Windows Phone and Windows RT would be a natural step now that the two operating systems are under one roof at Microsoft and a "Modern" version of Office appears to be in the offing.
Is there room at Microsoft for an operating system that isn't licensed? There have been at least a few over the years, for its Zune and Xbox products. Perhaps the market for RT-based systems is so small that Microsoft -- or a single partner such as Nokia -- would be the only taker, at least as an intermediary step. This kind of strategy might work as a fallback for a while, but in the past, its operating systems that attracted few licensees (such as Portable Media Center and Windows Home Server) have not stayed around for long.
Without the benefit of backward compatibility, Windows RT offered the purest test of consumer acceptance of the new Windows touch experience on larger devices; its support of the same ARM processors used by Android tablet makers was to level the playing field. Regardless of whether it lives on as is, gets dropped or merges with Windows Phone to expand its reach into handsets, its lack of acceptance should serve as a wakeup call to Microsoft. The company must do more to reach tablet customers looking beyond backward compatibility with desktop applications.
Ross Rubin is principal analyst at Reticle Research, a research and advisory firm focusing on consumer technology adoption. He shares commentary at Techspressive and on Twitter at @rossrubin.