I debated on whether to answer your question wearing my fandom-cheerleader disguise, or to tell you what I really think. Sadly, the pompoms are in semi-retirement, and I don't think we'll get any truly meaningful scenes between Jack and Sawyer until S6. That said, though, when I retired my cheerleader icon I replaced it with a glass-half-full, and in that respect I think that their relationship will continue to develop while they're apart. Maybe now they've finally hit bottom with the jealousy bs and they can move on from Kate toward understanding and respect. I really, really hope.