First, the Orchid station. It's a chemical processing plant that can release deadly gas on the whole Island, right? Dharma must have been planning their own purge. Taking out the Hostiles seems a likely reason to build such a facility. That's why the Swan was built. Think about it, the two are being constructed simultaneously, and the Swan is sealed off with "quarantine" signs because the team inside of it will be gassing the Island (which is why Radzinsky is so spooked about the Hostiles learning of its existence.) The only thing that stops Dharma from successfully "winning" the Island at this early point is "The Incident," which forces them to repurpose the Swan as the world-saving button-pushing station.
I've been trying to formulate a good hypothesis for The Incident for a couple of weeks now, since that seems to be where this season is heading as a culmination. My initial feeling, which I still think may make the most sense, is that the Losties somehow cause a rift in the space/time continuum (or a Wrinkle in Time...), and the button-pushing is some sort of temporal regulator. This could work one of two ways. First, which fits Daniel's explanation (and the skipping song,) is that the Island's time really is like a record, and every time the needle closes in on The Incident, pushing the button effectively skips it back 108 minutes to a smooth part of the record. This would require a "fold the paper of time, then push a pin through it so it connects two points" bending of the time-line so that the button pushing in the '90s would be effecting The Incident in the '70s, which only seems feasible on this Island. A second way would be to somehow isolate that portion of the ! time-line whenever the button is pushed, where doing so keeps that moment/series of events from ever connecting with the rest of the time-line where it would have taken place. It would then be playing out, over and over, as a permanently skipping groove of the record, in the safety of its own parallel time bubble. Of course, as has been widely speculated, Jughead could also play a part in this. Maybe that's the incident that has been isolated? OR, as we near the end of the season and see stations Orchid and Swan nearing completion, perhaps something goes terribly wrong with Dharma's attempted purge, which would explain why the Swan was so conveniently located to be repurposed as a containment device.
I've been trying to formulate a good hypothesis for The Incident for a couple of weeks now, since that seems to be where this season is heading as a culmination. My initial feeling, which I still think may make the most sense, is that the Losties somehow cause a rift in the space/time continuum (or a Wrinkle in Time...), and the button-pushing is some sort of temporal regulator. This could work one of two ways. First, which fits Daniel's explanation (and the skipping song,) is that the Island's time really is like a record, and every time the needle closes in on The Incident, pushing the button effectively skips it back 108 minutes to a smooth part of the record. This would require a "fold the paper of time, then push a pin through it so it connects two points" bending of the time-line so that the button pushing in the '90s would be effecting The Incident in the '70s, which only seems feasible on this Island. A second way would be to somehow isolate that portion of the ! time-line whenever the button is pushed, where doing so keeps that moment/series of events from ever connecting with the rest of the time-line where it would have taken place. It would then be playing out, over and over, as a permanently skipping groove of the record, in the safety of its own parallel time bubble. Of course, as has been widely speculated, Jughead could also play a part in this. Maybe that's the incident that has been isolated? OR, as we near the end of the season and see stations Orchid and Swan nearing completion, perhaps something goes terribly wrong with Dharma's attempted purge, which would explain why the Swan was so conveniently located to be repurposed as a containment device.