Did this come true?
"By now any seasoned .NET developer is used to getting their hands dirty by mixing Win32 unmanaged code (necessary for shell/OS integration) with pure .NET managed code. Fortunately this will all soon change with WinFX, a pure .NET “managed” operating system and API, that will finally remove the dependence on Interop, and provide access to the base operating system in managed .NET code"
Also see:
http://blogs.msdn.com/b/somasegar/archive/2006/06/09/624300.aspx