Just in case you care at all, the September 19 Mayweather-Marquez undercard feature between Michael Katsidis and Vicente Escobedo will be for the interim WBO lightweight title. Juan Manuel Marquez currently holds the "full" or "super" or "regular" or "whatever" WBO title, but won't be fighting at lightweight for a long time, at least, since he's got the catchweight fight with Mayweather and who knows after that? I guess if there's a time and place for interim titles -- and there really isn't, to be honest -- this is one of the situations where it's not the worst thing.
I do really like the Katsidis-Escobedo fight and am thrilled that it'll be on that undercard. If Mayweather-Marquez turns out to be the snoozer some are predicting, the show will need some genuine action on the undercard and these guys could provide that. Katsidis is all guts and blood (not blood and guts), and Escobedo had a hell of a good fight with Carlos Hernandez at Lightweight Lightning in April.
By the way: Is this a continuation of the Lightweight Lightning "tournament"? What a crock that turned out to be. Escobedo and Katsidis did win "first round" matchups, as did Rolando Reyes and Edwin Valero. But even then word was that if Valero won, he wasn't staying in "the tournament," and Reyes was a late sub they probably didn't want to win, so if you take out Valero and Reyes, I guess we have the Lightweight Lightning final. Hey, I'll roll with it.
Katsidis has actually held the interim WBO title before, when he defeated Graham Earl in a hell of a fight back in 2007, and then defended it in an even better war with Czar Amonsot. He lost it when he took a crack at Ring world champion Joel Casamayor in March 2008, and lost another world title fight (if you consider the IBO legit, anyway) when he came up short in September against Juan Diaz.
Escobedo, on the other hand, has never fought for a title, not even one of those extra useless regional belts. In fact, this will be Escobedo's first 12-round fight, but he has gone the 10-round distance on five occasions.