Metro-style Internet Explorer 10 Ditches Flash, Plugins(September 16, 2011)
"The Metro browser in a peculiar position"
Windows 8 will have two versions of Internet Explorer 10: a conventional browser that lives on the legacy desktop, and a new Metro-style, touch-friendly browser that lives in the Metro world. The second of these, the Metro browser, will not support any plugins. Whether Flash, Silverlight, or some custom business app, sites that need plugins will only be accessible in the non-touch, desktop-based browser.
Internet Explorer 10 Ditches Flash
Should one ever come across a page that needs a plugin, the Metro browser has a button to go to that page within the desktop browser. This yanks you out of the Metro experience and places you on the traditional desktop.
Microsoft has been vigorously promoting HTML5 for the last year and a half as the best way of providing rich interactivity on the Web. HTML5 potentially has reach far beyond that of Flash, since it can target both conventional browsers and closed ecosystems (such as iOS) alike. However, until now, Microsoft's messaging has been tempered somewhat: use HTML5 when you can, but if you can't—if you need support for DRM-protected media streaming, for example—then it's reasonable to switch to an alternative, plugin-based technology.
A reasonable decision?
With Windows 8, however, those reasonable decisions to use Flash or Silverlight will now be heavily penalized. Technically, there's nothing wrong with the desktop browser, of course; the rendering engine and performance will be identical between both Metro and desktop. But the experience will be substantially inferior. The desktop browser isn't designed for touch inputs, meaning that users will either have to switch to a mouse and keyboard, or fumble around with an interface that wasn't built for fingers. The switch to the desktop browser also appears to discard things like back button history and current page state.