Williams says he can make 147 lbs. The fight should be fought there. That would be an entertaining fight. Williams would get beat up though. He doesn't move his head, he doesn't jab all that well, he has no defense, he fights the same way everytime, and he's wide open for counter shots. However, he has a lot of heart and throws a lof of punches. It would be a very good fight. I don't want to see Mayweather vs. Martinez. It would be two counterpunchers going at it. Many people would be dissapointed by the fight.
Not for Mosley. He may have 6 losses but only lost to 4 people(Forrestx2, Wrightx2, Cotto, and Mayweather). He hates to lose and usually performs better in rematches as proven in Wright 2 and Vargas 2(yeah Vargas was shot but still Shane moved and did better).