I got say their is noway Williams beats Margarito in a rematch. Williams was getting the business in the 2nd half of that fight and it was him that was more beat up. Margarito got basically a wake up call (Starting off slow) by that Williams fight. In turn it helped him beat Cintron, Johnson, Cotto in the fashion he did ie get going from the get go. Will it be a great fight? Yes. Margarito tho will get him in the end. When Margarito beats Williams he will call out Mayweather for the unification and become undisputed (Oscar is gone and their is no more big money fights out their for Margarito besides Mayweather and Cotto) Mayweather said himself that he would fight him when it was bigger well this is what Mayweather meant. The haters will hate Money May but belive me Mayweather will fight Margarito once Margarito takes care of Williams (Which i belive he will) Mayweather maybe a business man, but tell mewould you not buy the the Margarito vs Mayweather PPV once Margo takes care of Williams? He would become the #1 man disposing of Cintron 2,Clottey,Cotto,Williams? Mayweather vs Margarito would be a super fight for all the marbles which is what Mayweather wants.
If Margarito starts fast he definitely could take the rematch. I think Williams is slick enough to win though. The punch volume and stamina he has are something Cotto didn't have.
If I remember correctly Margarito vs Williams was an open-air fight and it was also during the day, maybe this affected Margo and could account for his extra-slower(than usual) start.