But I think the movement is significant and can’t be overstated. And recent developments are really even making it more and more interesting.
Of course there are the critics.
Developing for the desktop (or tablet) will most likely always be pretty different than for the web. For Metro style apps there will be a lot of new concepts, libraries and tools that are different to the ones that are used in web development (just have a look at WinRT, WinJS …).
Of course another interesting thing will be to see how Metro style apps will change the architecture of future desktop applications. I think some concepts from web development will get adopted into desktop development. A stricter enforcement of separation between UI- and backend-components within a single application will most probably be a result (i.e. there seems to be no notion of traditional data-access in WinRT).