I think that if Nintendo wanted to go after RHDN and order us to shut down, there would be little we could do about it, but it wouldn't destroy the romhacking scene (ahem, backups and private messaging).
Basically, when you look at the bare facts of the idea, there is no real way to stop filesharing, in the end-all-be-all of it, short of declaring internet access illegal. I don't even know what kind of infrastructure would be necessary to enforce such an ultra-draconian law, and the infrastructure that is currently in place in the world can barely resolve traffic issues in major metropolitan areas.
I remember some spy-ish movie or something where a guy was talking about a computer virus called 'Ice-9' that would shut down all computer network activity in the world. That's a cheesy, comic-booky super villain plot, not a realistic expectation at this point.
We are networked at this point. Humans sure do love to resist change, though.