There was never any doubt Firefox and Chrome would come to the Windows 8 Metro Start screen. Both Firefox and Chrome work fine with the Windows 8 Consumer Preview legacy desktop. We haven't seen Metro versions yet, but they're on their way.
Firefox's Brian Bondy confirmed late last week that work has already begun on a Metro-style version of Firefox. Yesterday a Google spokesperson confirmed to Mashable that Chrome, too, is coming to the Metro Start menu. Neither the folks at Opera nor Safari's handlers at Apple have made it official yet, but it seems inevitable that they'll also put on a touch-friendly face. All of this is made possible by an open invitation from Microsoft for developers to hook together Metro-style and legacy desktop versions of their browsers.
But Metro has a "no add-in" restriction for Metro browsers, which by default bars Flash. There's a loophole in the spec, though, that has me wondering whether some smart browser programmers will find a way around it.
Microsoft published a white paper a couple of weeks ago that includes ground rules for "Developing a Metro style enabled Desktop Browser." Browsers occupy a unique gray area in the Windows 8 milieu: They "may be designed to access both the Metro style experience as well as the traditional desktop experience." Although the Metro side of the browser runs in the now-familiar full screen Metro "immersive" part of Windows 8, the browser is also granted "full access to Win32 APIs for rendering HTML5, including the ability to use multiple background processes, JIT compiling, and other distinctly browser-related functionality (like background downloading of files)."
No other apps in Windows 8 are allowed to straddle the Metro-legacy desktop fence like that. The pairing of Metro-style and legacy desktop browsers may open up a whole world of interesting possibilities. What's to keep a little Metro-style browser from calling its big legacy desktop twin and handing off the dirty work -- the stuff that requires add-ins -- to the desktop version?