I don't really get all the hoopla about the Metro UI. When it first appeared, I thought that it was going to be a dumb POS that would never work for a desktop or laptop machine. But I was curious and wanted to take advantage of Win8's other performance improvements, so I gave it a shot.
Well, I happen to like it. It is as fast as the old Start menu...one click to open it, and then one more click on the tile (shortcut), same as before, but with bigger icons and what I think is a cleaner layout. So personally I think that the Metro UI makes perfect sense and I use it on my personal PC and my work machines. It has not hindered anything, and it feels nice and fluid.
Is it "innovation"? Hard to say. Considering the other nonsense that counts as "innovation" these days, like apps that let you find hook-ups nearby and tweet your dog's dog food preferences, I'd say that this counts if that's the bar something has to meet.