First we had a few leaks from Windows 8, which showed that the Metro UI interface design concept, with its minimalistic footprint, is heading for the world's most popular desktop OS.
Metro UI, inspired by the clear-cut and easily understandable transportation signage in airports and metro stations, initially appeared in Windows Media Center, then made its way into the Zune Player, and its final, most comprehensive appearance was in Windows Phone 7.
A mock rendering of Windows Live Essentials dressed in Metro UI also reaffirms that people dig this type of unobtrusive interface, and would like to see it throughout the Microsoft universe. These are just a graphic designer's dreams, but they surely make the real thing look cluttered in comparison.
Now, we don't know if the simple font and uncluttered space - perfect for touchscreens - will be plastered all over Windows 8 and Office 15, as well as Microsoft's cloud services, but it might as well be, at least when you are using or visiting them from touchscreen devices. From what we've seen so far, Windows 8 for the desktop looks like Windows 7, with slight variations in the Aero theme. However, we also know that these milestone releases don't usually include the final interface either, which gets wrapped around for the RC versions, so the full touch interface leak is probably a few months away.
Most likely, Windows 8 for the desktop will mostly look like the predecessor, but the one for touchscreens will have a totally different wrapping - the Live Tile-based interface, which is now codenamed Immersive, and the Metro UI concept will be oozing from every menu. A few screenshots from a leaked milestone version of Windows 8 suggest just that. Here's the Immersive browser, wrapped around like the one in WP7, but actually being a full desktop IE9 browser underneath.
source: WinRumors, WithinWindows & TechTrends