It's only a megafight because of the name Delahoya.

Hatton vs. Cotto is a bigger megafight because it actually moves boxing forward. Delahoya Mayweather never would.

Delahoya wins, he retires, Floyd has an L, continues on.

Floyd wins, Delahoya retires, Floyd has another title, goes back to fighting.

Whoever wins is not going to capitalize on it, if Delahoya wins he wins but he doesn't move boxing forward one bit since he isn't gonna stick around whats it do for boxing besides give Floyd a loss? its not like anyone's gonna do something about it. At the very least any other opponent could capitalize on that victory and build their own legacy and I really don't see why a guy who's legacy is already written would do anything for boxing to beat Mayweather. I really don't.