Updated (4:30 p.m.) Added stats and images for loot.
After a small launch hiccup, Mafia Wars San Juan is, indeed, on... for most, anyway. If you don't have access this new fighting event yet, it will be rolling out slowly to everyone.
Much like the Beat the Feds event from a few weeks ago, you'll take on four tough Puerto Rican bosses. You can call on help from mafia members to fight each boss and after they're beat, you'll score a mastery item, along with XP and Vegas chips. Each boss can be beat three times, and each time you beat them, the mastery item from that boss will gain higher stats. Once you beat all of the bosses, you will earn another rare item -- the Mastery Outlander.
Senor Carazco: Throwing knives (Weapon) 30 A, 43 D
General Vargas: MC Gloss 350 (Vehicle) 57 A, 95 D
Don Ramirez: Night Vision Viewer (Armor) 106 A, 71 D
Big Lou: Red Piranha (Animal) 110 A, 82 D
Mastery Reward: Master Outlander (Special loot) 112 A, 58 D
Oh yeah, and there's a time limit. The entire event will only last for 10 days, and once you start to fight a boss, you only have a certain amount of time to beat them.