In Ember, for instance, it's perfectly easy for a "computed property" on a View object to return the value of an attribute on a DOM node. In this model, the DOM is the "canonical" representation of state (also fulfilling HATEOAS if "real REST" is your thing). This is a perfectly fine way of doing things, and is possible in Ember or React or any of the above frameworks as far as I'm aware. How the binding between javascript and DOM is registered is entirely up to the library developer.

In my ideal world, I want the performance of the Virtual DOM / rAF batching described in the blog post, I want web components as the underlying DOM / markup that represents my views, and I want to wrap them with Ember-like computed properties and routing structures. But hey, while we're asking for everything, I'd also like universal flexbox implementation, Clojure-to-asm.js compilers, ES6 generators to finally come out...