I'm not sure they want those to disappear. Some of Microsoft's own products are written using Win32, like Office, and Internet Explorer. I think this is more about providing a C++ compiler for developers that are unable to spend the $499 on Visual Studio Professional.
Because they keep acting like it. As say this as someone who develops Windows desktop apps. You might have valid counterarguments to that, but that is the perception I have and I don't think I'm alone.
I really think it's just that Metro/WinRT is the new thing, they're always going to be trumpeting the new features of the new release as if they're the only thing anyone should care about, that's unfortunately a Microsoft habit. The desktop will quietly continue to persist and evolve.
I don't expect much success with Windows 8, due to a combination of there being a lot of genuine rough edges and gaps in the new environment and in how it relates to the desktop, most people not really feeling a need for a new version of Windows right now anyway, and people's normal resistance to change. However, they'll probably continue to improve the Metro stuff in future Windows versions, and eventually it will just become another boring established part of Windows that everyone takes for granted. At which point it won't be the new shiny anymore and balance will be restored.
