"The Betrayal of Jimmy" will be available exclusively for the PS3 at launch, free with a code inside the new game, or from PSN for $9.99. The pack will allow players to experience "dozens of intense newly created arcade-style, city-based missions" as Jimmy, a mob mercenary. "Jimmy's Vendetta" is another pack coming down the line (pricing and availability not yet announced) that will offer new locations and new missions and have the player working alongside Jimmy around Empire City.
Those previously leaked trophies are for the second pack, then, not the first. And we don't yet know if that pack is exclusive to the PS3 or not. Hey, it's confusing, but you're no mafia meathead -- you gotta be smart to outwit the feds, see?