Windows RT is Windows
I know its trendy to deride Windows RT. It not "real" Windows, it doesn't run programs like Photoshop or allows you to use Chrome (precious,precious, crash prone Chrome). It doesn't have the apps. It confuses people (even though I suspect they think tablets ARE computers). And there is Silvermont/Bay Trail coming down the pike to obliterate it.
And yet Windows RT is Windows. It shares the same run time as Windows, it has the same NT kernel, and except for the fact it can't run programs built for x86 it can function as a proper Windows machine.
Right now RT (in my opinion) is a weaker sell than a x86 Windows device only because of backwards compatibility. I don't think about Windows RT in the same way as Windows 8; I do see it as a tablet/mobile OS similar to Chrome OS and iOS. Given the way ARM architecture is moving I think RT is the right call for the long term and gives Microsoft some flexibility.
I do think Microsoft mishandled how to sell RT and where to position it in the market, but I don't think they should've waited. I do think they will reposition it.
Windows RT has the benefit of providing some of the PC functionality people want with the benefits of using mobile devices and hopefully 8.1 improves on it.
So to sum up RT is a part of Windows and its future, its strategic, and its an extra option for those that want it.