Either Manny will stop Floyd in the 8th to 11th round or Floyd will win by decision.

The referee will not stop the fight in the 12th round even if Floyd is being beaten up as long as he remains standing. But the referee will probably stop the fight if it's the other way around. Even if Pacquiao dominates, a decision will go in Mayweather's favor, similar to what happened in the Pacquiao-Bradley I fight.

And Floyd is not going to intentionally lose this fight just to get into a second fight. He is not going to risk losing the zero and there is no guarantee that he will win the rematch.