Nice theory, but it seems in reducing to practice the minimalist, form follows function aesthetic got lost somewhere along the line. All that distracting motion and bright color in slide 44+ looks more like a childs paint-box or Gaudi's tiles in the Park Guell than something Mies van der Rohe might have conceived. The theatre example is certainly a bold use of typography, but as a means of conveying information clearly or quickly it sucks

Overall I like the concepts behind Metro, but I think it still needs that Jobsian obsessiveness to really work  If you want the tile layout to actually be beautiful in the real world, then you are going to have to apply a little more control over the elements that can get posted there; for example constraining the palette to two or three theme colors (with adequate contrast), avoiding arbitrary bitmap images, and outlawing or severely restricting how and when animation happens.