I think Mayweather will win this one in a decision. He's too quick, can pack a solid power punch, and is simply too
good right now - he's 37-0 with 23 KO's. De La Hoya was great is is still pretty good right now, but I can't see him beating Mayweather, unless he gets very lucky with a left hook. Mayweather has wanted this fight for the longest time and I feel he is more hungry than De La Hoya here.
The one thing bugging me is the eerie parallelness to Rocky III, except that there is only one fight here, not two. De La Hoya is nearing the end, is adored by fans, has the intangibles, and is a nice guy. Meanwhile, Mayweather is very cocky, says he will crush De La Hoya (among other things) and personifies the role of the "bad guy." You can also say Mayweather trains alone (like Clubber Lang said), since there is instability in his corner in terms of his trainers. In the movie, Rocky wins in the end...will De La Hoya win here?