My primary concern with this is that different applications are inherently optimized for the platform on which they were originally designed. There are some applications that have a very dense UI because there's simply alot of functionality that the program handles (think of a video editor, an IDE, etc). Trying to slim down those applications to make them reactive so that they will scale onto a phone or tablet just s…
This mode seems suited for mobile UIs, so that flexibility should get them pretty close to being convergent. There probably still need to be some adjustments to make it really usable on mobile, but a lot of the work has already been done.