There'll be two kinds of applications for Windows 8, one that runs in a traditional desktop, and the other pseudo-mobile apps based on HTML5 and Javascript, but both environments -- rather, the entire OS -- have been designed from the ground up for touchscreen use. Keyboard and mouse will still be options for both sets of programs, but there are multiple virtual sets of keys for different form factors, including a split keyboard for vertical slate use. Multitasking is simply a matter of swiping running apps into the center of the screen, and you can pull windows partway to "snap" them in place alongside other windows -- even mixing and matching traditional desktop programs with web apps simultaneously (like Twitter alongside your spreadsheet). There's a new version of Internet Explorer 10 (which runs Silverlight) and an app store built into the touchscreen interface, along with integrated services like Office 365.
