Who has Mayweather fought at welterweight? Um he fought a much faster looking, a sharper Zab Judah then the one that fought Cotto. Cotto punches harder than Mayweather of course he has been able to take out guys that Mayweather hasn't (Sosa, Corley) that doesn't mean a thing. Moving up to 154 to face Oscar Dela Hoya is a way bigger threat to Mayweather than facing Cotto, and you want to know why? Oscar is faster than Cotto, he has a many of the same skill sets as Cotto, he is a little better at boxing on the outside, and he has a way better chin than Cotto. I think Cotto has certain skills that Oscar doesn't, but to fight Oscar is to be in the spot light and Mayweather had never been in the spotlight like that before. IMO guys like Zab Judah present more of a problem for Mayweather for then Cotto in many respects, first of all Zab is the closest guy to measuring up with mayweather in the speed department, Secondly MAyweather comes forward against Southpaws which he definitely isn't as good at doing as countering. Mayweather also fought Baldomir, an albeit slow but industructible welterweight, now I think a few guys can beat Baldomir, but not like Mayweather did, Baldomir landed 12% of his punches in that fight where as he was landing WAY more regularly on Judah. Mayweather also fought Ricky Hatton one of the guys people felt was the most dangerous of anyone he could face because of Ricky's footspeed, pressure, and inside fighting ability, yet Mayweather beat him in every aspect of the fight.

I am sick people who think that Mayweahter isn't taking challenges, you would have to have your head up your ass to not think he is facing quality opposition. Cotto-Mayweather will come, but not this year, next year Mayweather will face Cotto when Cotto is more well known after fighting Mayorga and Mayweather will beat Cotto because he is too fast, and too good.