It's getting closer and closer for Mayweather to really think about what he needs to do with the rest of his career. Closer in terms of age, fan loyalty, and promoters losing faith in his abilities. I know he's going to fight Ortiz in September, but if he doesn't fight Manny sometime next year then its not going to happen.
Manny doesn't need the money anymore. He's a billionaire in the Philippines and a Congressman at that. He wants to run for Governor in the next election and will most likely win. Manny isn't going to risk his health in the ring for much longer if its going to affect his ability to help his countrymen as a public servant.
If Mayweather never fights Manny he's going to regret it for the rest of his boxing career and his life. It's going to haunt him forever. Sure, he's going to be in the boxing hall of fame someday but the shadow of not fighting Manny will follow him forever.
Go for it Mayweather. It doesn't matter if you win or lose. Losing to Manny is better than being haunted forever for avoiding him and winning will cement your legacy. What's that Nike saying? "Just Do It"