Does anyone else remember the other time one of the LOST characters described the island as a cork? I think that it was Daniel Faraday that said that the island sat on a large quantity of electromagnetic energy, and that the island acted as a cork, keeping it all trapped. If it ever got out, it could be disastrous, even leading to the destruction of the world.
When the DI drilled into the Swan site it started to release some of that energy, which led to the incident (I know that a lot of people think that the incident was the Jughead explosion, but that hasn't been revealed yet). So the end result was that someone in the Swan station had to always push the button in order to keep the energy trapped, thus saving the world. Desmond eventually destroyed the hatch, permanently pushing the "cork" in place.
Here is where both analogies of the island as a cork come together. The numbers that were entered to push the button all correspond with the candidates who could replace Jacob. Anyone of those candidates could become the new Jacob, thus keeping MIB from leaving the island, just like a cork.
Am I crazy for thinking of this?