Unity - not unlike some other game engines - provides as the backbone of its architecture a scene-graph that unifies all aspects of the MVC / MVVM triad. Trying to work around such fundaments of the platform will only cost you more in time than you think you might gain by adapting it to the architectural paradigm you mention... rest assured.
Re your question on GUI: This depends very much on which Unity GUI system you are using:
IMGUI requires you to make GUI calls on every update -- thus there is no "retained mode" data binding.
Retained mode GUI for v4 should retain the values you put into them, but that isn't the same as data-binding. You'd need to explicitly update the values.
Unity 5 (due around July 2014) will provide access to the new GUI system. Being NGUI based, you'll have access to data-binding, as you can see that NGUI has for some time supported data binding.