Would obviously be great for Maidana, it will be the biggest achievement he has ever done and can ever do. Mayweather will most likely aim for an immediate rematch.
Mayweather: Wouldn't do all that much for his legacy. Everybody loses and he's certainly not at his peak anymore at 37. The fact he hasn't lost yet is incredible. It wouldn't take more than a couple years for even his biggest critics to acknowledge such. The only thing that will be completely strange for a new boxing fan studying up 50 years from now is if he actually ever does retire undefeated; not if he had ever suffered a loss... Maidana: Would make his name never forgotten in history even 50 years from now. He would become a hero to the majority of boxing fans everywhere. Taking Mayweathers' zero at this point is in some ways as significant as taking any fighters' zero throughout history in the minds of many being that he is probably more accomplished than any fighter ever has been at the time their zero was taken.
It would be the defining moment of Maidana's career and would lead to a rematch against Floyd and possibly a fight against Pac. If Floyd loses, he can either retire with his head held high or have an immediate rematch. If Floyd won the rematch decisively, It would actually look good on his resume that he beat a fighter that had proven he was capable of beating Floyd.
We've already seen what some of the short term carnage is in today's day n age when KTFO6 happened. It'd be dramatic. But time heals everything and allows for perspective. I don't think there would be any excuses as the poster above states other than Floyd is 37 years old and not what he once was. EDIT: Which is not an excuse. Father Time is the end all be all; not an excuse but a reason.
And what happens if a meteor strikes the earth? It's so impossible that it's not even worth giving a cent. Maidana can't crack and can't boxe, that's it and that's all.
I wonder if Mayweather has a rematch clause? I would assume so. A rematch between Maidana-Khan (assuming Khan wins) would then become I think the next logical fight.
more chance of pigs wearing boxing shorts and gloves flying..... maidana will not even win 1 round he will get stopped early