Im not entirely sure what Brock's motivation will be anymore. I doubt he ever expected to win the UFC title but it was pretty much handed to him on a plate and he rose to the challenge. He doesnt have the experience to beat JDS or Cain. Or even Carwin for that matter. Would be good to see him whup Mir again though.
Guys can only do that to Brock if they can stuff his takedowns in the same way Cain did prior to unleashing.