Nice for the devices and drives section. Too dark up top, though I suppose that would part of configuration/theme. It has promise as an idea, but unlikely to see an implementation like it from Microsoft.
Looks clean and simple at first glance. I think for tablet mode all the icons can be at least 50% bigger. The reality is on mobile tablet devices those sizes are too small and dysfunctional for a good touch experience. For that matter I would also say to also increase the space between the file locations in the left column. I'm curious to see what your design would like in portrait mode.