I'd bet my house that UFC puts together Nelson/JDS II.
If they intend to do Werdum vs. Cain should the former win his next fight, then the winner of Big Foot/Overeem should face JDS in the interim. But I can say with confidence that if Overeem wins, he'll either get the next title shot with Fabricio waiting in line, or vice versa. So who fights JDS if not Big Country, the only other semi-winning HW on the roster?
I still think there's more money in Overeem vs. JDS than Overeem vs. Cain.
Edit - Completely forgot about Mark Hunt. I'd love that fight. Two hard punchers, though I suspect JDS has the better chin. I'd be sad to see one of them lose, lol.