I haven't looked closely at Hyperloop, but I thought it was meant to be a JavaScript-to-native compiler. NativeScript looks more like plain old Titanium: run JavaScript in V8, with an interface to native UI (and other) APIs.
The point is where the Titanium-esque part is built: kernel-land (native) or user-land (JS)? In Hyperloop/NativeScript (as far as I can understand NativeScript) it is done completely in JS-land, so there’s no difference between Titanium code and app-code. In plain old Titanium (Ti.Current) the bridge is in kernel-space.
I would also be willing to try it, provided I didn't have to register with any services to do so