I have a theory about how things will develop .... the "Oceanic Six" (or whatever the number is, seven?) are the only survivors who make it off the island ... the rest are left behind, and are "lost."
The "rescue" will be a harrowing effort - maybe through hijacking this "freighter" we're hearing about. At any rate, when these six people (Hurley, Jack and Freckles are obviously three of them) are finally rescued, search teams won't be able to find the island or the other people.
.... that's all I got