It doesn't interest conspiracy theorists alone. This also raises a national security issue for every country in the world. If they ever happen to be in some kind of political crisis with the USA, there is always a risk that the NSA can issue a command that will freeze all Windows 7's in the target country. All critical systems are of course isolated but an attack such as that would greatly hinder the civilian computer infrastructure. If Microsoft had been collaborating with the Russian FAPSI or the Chinese MSS, NSA would be trembling in their boots.