I wasn't interested in Windows RT, I'm not interested in Windows 10S. 10S has even less of a reason to exist than RT did, at least RT was a (supposed) hardware reasoning. What reason is there for 10S? Certainly not security or streamlining.
I wouldn't say no to a Surface tablet, or the Surface Book though. Tying the Surface Tablet to 10S with a "choice" to upgrade isn't an appealing proposition.