I do feel Cotto is a strong opponent for Floyd as his last few performances have been solid and he seems to be comfortable at this weight. Since at 154 he doesn't tire as easy in the later rounds which many feel is the danger zone for Cotto against Mayweather. Still, Mayweather will come out victorious if its by KO or decision.
You can see that Mayweather has a lot of respect for Cotto but the trash talking side of mayweather will come out on 24 7. Like Mayweather said, there is many sides to Floyd Mayweather and he is all about pleasing the fans so I'm sure he will have plenty to say nearer the fight