Observables has moved to WHATWG [1] and been implemented in Chrome, although I don't know if the other browsers have expressed any interest (and there's still some issues [2] to be worked through).

But Observables really do not solve the problems being talked about in this post.

[1] https://github.com/WICG/observable [2] https://github.com/WICG/observable/issues/216