Money May is back, controversial as ever. If you're looking for commentary on Mayweather's place in boxing, Doug Fisher's been on a role lately. I can only add that Mayweather complains that the press treats him differently than Pacquiao and Latin fighters in general, but that's really silly; Pacquiao and the Latin fighters Mayweather is talking about (presumably De la Hoya) don't run around calling themselves the best in history while avoiding the hardest challenges for five years. If Mayweather would just stop making excuses and fight some combination of Mosley, Cotto, Pacquiao, and Paul Williams in his next two or three fights, I, and most everyone else, will stop ragging on Mayweather, even if he loses.
As to his fight with Márquez, I think the Mexican wizard could steal some rounds if Mayweather is rusty. I also think Mayweather is going to fight in a style and at a pace that really favors Márquez. He won't put the pressure on him too much, he'll give Márquez an opportunity to make adjustments (which he does as well as anyone in boxing), and the output should be low enough that a few good power shots every three minutes should be enough to carry the round. At the same time, the rust factor will probably even out, because Márquez is fighting so far north of his ideal weight. Furthermore, everything Márquez does well, Mayweather does equally well, but with more speed and power. Both guys are equally smart boxers, so you have to go with the guy with the ample size and speed advantage, which is Mayweather. I think there will be competitive moments, but Mayweather is going to take a relatively comfortable unanimous decision.
The only wild card could come if Márquez tries to adopt a more aggressive style, a la the traditional Mexico body banger. He's never fought like that before, but if he's come to the same conclusion that I have above, he might figure that imitating José Luis Castillo is the only way to beat Mayweather. I think that would vastly increase the chances of a knockout victory for Mayweather, but getting out-hustled is the only way I can see Mayweather losing.
On the undercard, I'll take Vicente Escobedo over Michael Katsidas and Chris John over Rocky Juarez, both by way of decision.