Check the full article for more Windows 8 details; also see Three Things We Still Don’t Know About Windows 8
At the heart of the new interface is a new start screen that draws heavily on the tile-based interface that Microsoft has used with Windows Phone 7. All of a user’s programs can be viewed as tiles and clicked on with the touch of a finger.
Windows 8 essentially supports two kinds of applications. One is the classic Windows application, which runs in a desktop very similar to the Windows 7 desktop.