One bit of speculation that passed through my mind while watching Pop-Up Lost: what about the woman Jack saved on the bridge? (Mrs. Arland? I don’t have a spelling.) This is Lost, after all: surely she wasn’t just a random stranger. What’s her connection? How and where is she going to come up again?
A quick Google search turns up one theory: that she is Juliet’s sister, with her miracle child, now older. Maybe this question has already been analyzed to death, or maybe Cuse/Lindelof have answered it and I’m not aware of it. But be generous to me! ‘Tis the spirit of Lost Day!