The current reality of RT is that the apps aren't there yet and the devices it runs on are underpowered. I often browse through the store, and I'd say that for every one good app I find, there's twenty more that are garbage; usually RSS readers or an app that has extremely limited functionality and a crappy UI. And there's no ARM device that rivals the performance of an x86 device in the ways that matter to most people who use RT and will use it, again, app selection and performance.
The future reality is that it's the future of Microsoft computing. We'll start to see this vision a little more this holiday season, with the release of Windows 8.1, likely a new Surface RT, and perhaps a few other RT devices from OEMS. At the moment and near future, OEMs will focus on x86 devices partially because people still want the full version of Windows, whether they truly need it or not. And most OEMs haven't dipped their toe in the ARM world, probably because of the above statement, possibly because of sourcing/licensing/production issues. This will slowly change over time.
The benefit of RT is that it dumps the legacy of x86. This means that it's not vulnerable to the same malware, it loses the bloat associated with the necessity of running x86 apps, and for Microsoft it gives them a fresh start to build a new product. RT also benefits from running from much more mobile-friendly processors, which means thinner and lighter devices, and devices which are also cheaper. And to Microsoft, RT means that they have a hedge against Intel and AMD. I doubt Intel's Haswell and newer processors would have the performance they have if they didn't feel the heat from ARM manufacturers. That type of competition is great for us consumers. The last benefit of RT is that it's a truly modern mobile environment. It's made first for touch screens, syncs to the cloud, and is practically impossible to screw up, unless you start messing around on the desktop side. For that reason (and others) I think Microsoft will constantly push the desktop into the background. They tried to do it with starting in the Metro interface, but had to renege on that because it's still too early for Metro. Even though Window 8.1 gives you the ability to start on the desktop, it's still something you have to enable. In the future, we'll probably see the desktop relegated to an EXE that you have to dig for, similar to how Program Manager was hidden in Windows 95 until it was eventually killed off completely. This won't happen for a while though.
Personally, I got my Surface RT on the 26th and immediately installed all the updates and updated to the Windows 8.1 beta. This has been a great device for me, especially after exchanging my touch cover for the type cover. I can use Office, write, consume media, and even do a little web coding on the device. The compromises that RT has compared to x86 don't feel like compromises at all; and I think most people, particularly the type of person that buys an iPad over a laptop, would agree.