so the button controlled the electromagnetic field it seems. Well that we knew, but it released it in bursts rather than allowing it to just persist around the island. When Desmond did not get there in time, it released, stronger than it would if it WAS pushed, and the plane crashed. Now that our good buddy John made a certain hatch implode, the field is free. This seems why NOTHING works anymore, because the field is no longer in control. This is what Sayid was picking up with that satellite phone, the field, and it was interfering to the point where he could NOT use it. And probably why Naomi crashed... and the other small plane... and Danielle's boat... and Desmond's boat... though his and the black rock might also be explained by storms..

So how can they contact Naomi's boat?? Or anything else for that matter? It seems our losties are royally screwed.. at least for now.

I thought that once the hatch exploded and the giant electromagnet was no longer functioning that devices WOULD be able to work on and around the island. Like right after it exploded, Penny's search crew detected the island on their radar map or whatever. But I guess they were just detecting the large EMF disturbance instead and it wasn't radar.
But I guess it's just the mysterious electromagnetic properties of the island itself that are still causing that? Cause otherwise why would Naomi's copter still fail on her?

The swan acted as a containment unit, allowing the EM charge to build up and dissipate upon entry of the code. However, now that the failsafe key has been turned, all the energy has been released and can no longer be contained to allow for a "window" to develop that would allow for contact with the outside world. I think the swan acted as more of a dam, and now that is is gone, the electromagnetic field flows from the Island uninterrupted.