Source: All Things D [Consumer Preview announcement]
quote: Windows 8 features an extensively redesigned "Metro-style" user interface, optimized for touchscreens as well as mice and keyboards. A new "Start screen", similar to the one in Windows Phone 7, includes live application tiles. The start screen replaces the Start menu and the Start button, being triggered by the Windows key, and is also the first screen shown on start up. The user can go to the regular desktop, which is treated as a Metro app with its own "Desktop" tile on the Start screen. Starting a traditional desktop-based application also switches to the desktop. The Start screen also displays the user's name and picture.The Windows Store will also allow developers to publish their Win32 or "traditional desktop" applications; however, the store will only provide links to such application on their websites.