I know what Microsoft's attempting to do with Metro. What I don't know is what benefit it will have for desktop users. Merging their touch and desktop visual styles might strengthen Microsoft's brand, but I've yet to hear any plausible theories for how it will benefit (or even not harm) usability for desktop users. There's decades of HCI research that says touch interfaces should be different from desktop interfaces. So what's the upside for users? Why should they accept Metro, if not just because Microsoft has a monopoly?