According to this trailer, the key to all of Lost's mysteries is The Fray–which I think unfortunately makes Lost the new Grey's Anatomy.
Apparently, in season 5 of Lost, droning music masters The Fray take on a sort of Greek chorus role, describing the action from their perch atop a bridge through terrible, whiny song. It's a bold stylistic choice to make so late in the series, but whatever. It's Lost. Not everything has to make sense.
Either that, or ABC has some kind of awful pact with The Fray to use their music in promotions for all of their dramas. Their researchers are probably hard at work right now looking for shots of America Ferrara lying on the floor for a new Ugly Betty trailer/literal interpretation of this song by The Fray.