Someone a few threads back said that there's a million ways for Bethesda to take the site down and that just Beth reporting it or threatening them would be enough for whoever's doing this to back down.
It is a bit too elaborate for just "something" Fallout related. There is a possibility that it's for a mod, and if it is then it would have to be a very [censored] major one.
Also, I don't know about you or anybody else, but after this, people dressed up in power armor won't get me aboard the hype train. This entire site gets people to discuss it: the earlier rumors, its fakeness, its realness, solving the ARG, Fallout lore, etc.. A few clowns in cardboard power armor surrounding Todd Howard on a stage with action movie soundtrack by Inon Zur blasting in the background won't have this effect.