Windows 8 officially goes on sale this fall, but Microsoft has made its next-generation operating system available online for anyone who wants a sneak peek at the future of Windows. With a slick new interface of touchable, customizable tiles, the new Metro interface is built to help Microsoft compete in the fast growing tablet market. Apple's tablet hegemony is indisputable at this point, but it doesn't owe anything to the iOS's endless field of icons. In this play for tablet relevancy, however, Microsoft risks alienating its traditional base of desktop and laptop users. Because, as cool as Metro is, it kind of sucks without a touch screen.