Manny Pacquiao and Juan Manuel Marquez are in "serious ongoing negotiations," according to a report at BoxingScene.com/NotiFight.com, with Fernando Beltran of Zanfer Promotions saying that the fight is "close to materializing" for a December date.
The fight would take place at the MGM Grand in Las Vegas on either December 1 or December 8 (it appears November 10 is out for Manny, but will be a Top Rank date anyway), and would be the fourth meeting between the two Hall of Fame-bound living legends. Pacquiao is 2-0-1 officially against Marquez, but each fight has been so razor-thin that it's almost as if neither man has ever had any serious advantage over his rival.
Pacquiao-Marquez IV has seemingly been the fight preferred by Top Rank's Bob Arum, and it just doesn't appear as though there's been much serious thought given to a rematch between Pacquiao and Timothy Bradley. Miguel Cotto's name has also floated around, but I don't see any way that happens at the moment.
Marquez himself says he thinks the fourth fight is going to happen, and also says that he could face Tim Bradley in November if he does not face Pacquiao, but I don't believe that's really likely. After all, if Pacquiao doesn't face Marquez, he'd probably face Tim Bradley.
Pacquiao-Marquez IV is probably a good bit bigger in terms of money than Pacquiao-Bradley II, and that's the main concern for the promoters. If Manny put his foot down and demanded "revenge" against Bradley, I'm sure he'd get that fight, but so far it doesn't seem like that's a huge concern for him, either. And anyway, Bradley would be there next year for a rematch, more likely than not.
So for the moment, it looks like this is the fight that you could bet on happening, and not the Bradley rematch. That could all totally change by tomorrow, as these things often do. Personally, I'm betting on an official announcement during the Chavez Jr vs Martinez fight week in Vegas.