This is a really interesting approach - and I concur w/ elsen - it's not that far from wikipedia's current mobile implementation [1]
Last summer, I build a couple of MediaWiki skins; one based on Zurb's Foundation [2] and one based on Yahoo's Pure [3]
Both of these projects showed me many of the non-obvious challenges in redesigning Wikipedia; tabs, tables, and editor come to mind immediately. Cascading a new look&feel down to common (and uncommon) extensions is, of course, it's own level of effort.