The Cain we saw in that fight was a shell of his real self. He was over weight, slow and hesitant to pull the trigger.
The real Cain, AKA T1000 Terminator - is in your face from the get go, attacking you relentlessly with take downs, strikes, and ground and pound until you are done, finished, terminated.
I expect that T1000 killing machine to show up in the rematch and push JDS to his limits. I think he'll over whelm Junior with take downs and quick strikes and end up getting the TKO some time in the third round, with Junior being too exhausted to even get back to his feet.
I fully believe that Cain is one of the very best MMA wrestlers in the game and one of the very best p4p fighters in the world. I believe in his skill set and expect him to fully showcase it in all it's glory come the rematch.