It could be a spoiler, or it might not be anything. Still, I'm left saying WTF.

Go to http://oceanicflight815.com/ and click on the barcode.

Type in theislandiswaiting exactly like that.

I think there's some kind of virus or disease on that island that's making the stranded ones hear stuff. This is probably the same stuff that's making "the others" go apeshit. I have a feeling that Desmond has some kind of miracle healing power (remember when he asked Jack if he believed in miracles?)...and then the paralyzed chick suddenly could wiggle her toes.

I don't know how the hell Desmond found himself on that island, but he obviously quarantined himself from whatever's going on in the island. And he's definitely waiting for someone. Who, I don't know.