Cain's biggest weakness is his defense, unless he made significant improvements in that area, I don't see the fight going his way.
People write off the first fight as some fluke but look at the way he got caught, he does not move his head at all when he punches, he just never really fought someone who can exploit that hole in his game up until he fought JDS(well Kongo did at times).
Against someone like JDS, you need better defense, plain and simple. He's too easy to hit and JDS hits way too hard to be taking flush shots from him.
Of course Cain can win this fight if he is able to get the TD's and work his GNP, I just feel his defense is too lacking for him to really be able to implement his gameplan, every fight starts standing.