>>>Win 7 is the end of the line for a true multipurpose OS
So far, Win 8 is all of Windows 7 Plus the locked down stuff. I am assuming it will be many more generations of windows before they actually take out the core Win32 stuff on X86. Even the old 16 bit windows stuff worked right up to the 64 bit versions of the OS. I think the "Developers must register" is only if you want to distribute your app through the app store (which is the only way to distribute a tiled app). If all you are doing is playing you can still use the Visual studio Express tools to build and run any kind of app on your own machine including tiled apps. Regular desktop apps are developed and distributed the same way they always were.