By using tiles you can imagine a much smaller and less flexible platform.
It seems hard to imagine that Microsoft believes that this tile based user interface will be able to completely supplant the existing Windows desktop. Keep in mind there is no indication a “Metro Style” app is running in the background or no easy way to display multiple Metro apps on the screen at the same time (besides the splitting-in-thirds of the screen option they do allow). So goodbye Windows hello colorful DOS!
