Mosley was probably at his best at 135, routinely gaining 15 lbs after weigh in and was a mix of power, speed and skills. Mayweather had the same, but was a more cerebral fighter, not wanting to mix it up until he had the upper hand. Who wins?
Mosley. Mosley was a different animal at Lightweight with a dynamic and stiff jab, tremendous body punching, fast combinations and very quick footwork. Mayweather is never a great style match-up for him since he likes a guy to come forwards, but he still has the tools to pressure Mayweather and win the decision. His defence was good enough to handle Mayweather's rather simplistic offence, and I can't see Mayweather being able to assert himself enough to keep Mosley from jumping all over him. Clear decision for Shane.
I don't see a stoppage as, whilst Mosley was a very good puncher at 135, he wasn't quite a "home-run-hitter" and scored KO's mostly through accumulation. Mayweather also has a good enough defence to take the sting off most of his shots, and he's not really going to stand in front of Mosley or run into anything silly.
there are alot people on this board who are not really knowledgeable about boxing. Most people here have not really seen shane fight at 135. couple this fact with the idea that floyd is the younger fighter, and floyd's campaign as a lightweight is still fresh in the memories of people, they will naturally choose floyd. at 135, i go with shane btw bc at that time he was a better boxer than he is now.