I like Bisping by unanimous decision.
That's the only way I see Bisping winning, if he get's on that bicycle. He's not a KO puncher, Leben could probably eat his shots all day and he dosen't have the distinct advantage in anything other than maybe his striking is a little bit more refined. Bisping would need to stick and move because if he stays in the pocket too long he's tempting fate, plus, he's been rocked by the likes of Josh Haynes and Ross Pointon and out brawled by a one legged Matt Hamill. It's highly likely we'll see Leben by TKO, or Bisping via stand and pray.