That's my take too, that CERTAIN of the 815 people had been guided/herded onto that plane. What I don't get is how "the island" knew that Desmond would fail to push the button and open a window for 815. However, I do think that some of them were brought there, Hurley among them. I agree also that Hurley is a wild card, perhaps someone the island didn't expect to have the gifts he has. If they're brought there to see who can step up to the island's requirements as a leader, Hurley is seeing some of the same things that Locke and Ben do. Would anyone else have seen the cabin? Miles maybe.