Just bought an RT
I think Microsoft are pitching RT all wrong. It's a tablet operating system that has some great benefits. Can't run x86 code so no viruses, malware etc. Included apps are really good if you use them (news, finance, photo). You can get other apps from the store (Photo manipulation, Skype, The Register!!). I like it having the desktop - it's great for file manipulation - moving files around, connecting to shares etc. USB is great for plugging a camera in. All the things you'd use a tablet and I haven't mentioned Office yet.
Microsoft should be pushing this product on it's own merit. The Surface RT is a great bit of kit, solid and well made, fast (try the latest version with 8.1 preview), long battery life. It's not a PC so don't push it as one. It competes with iPad's and Android - not with x86 Windows (but having the same interface is great). At £279, it's £10 more than an iPad mini! If you are in the market for a tablet (and not a PC), then give it a try.