If not a direct answer I'd appreciate a hot/cold on this theory:

I've heard you have confirmed...
That there will be deaths this season, including one of the main characters, and that Jack's father WAS on the plane.


And in "Solitary" we learned...
There's a disease. And there are other inhabitants on the island and creepy voices in the forrest.


So I'm speculating...
Dying of the disease may not equal pushing up daisies. Starting with rash-guy we'll see it infect our survivors. Some will at least appear to die, but will come back...different. (But, to quote Shaun of the Dead, "We're not using the zed word.") The death will be one of our love triangle (Jack/Kate/Sawyer...maybe even Sayid) although probably not Jack because I think among the "changed" will be his father.