I think it was the third one, which also stated that there is like 30% more content added to the gameworld as a whole because of it. I'm wondering though, since the new missions focus on Johnny (who I've actually just had backstab me in the museum piece mission in the original campaign so I'm pissed off because that one was so fucking difficult ((I'm amazed I didn't die once on the first one)) and the subway tunnel on the motorbike one that follows I keep dying on) will we be able to switch back and forth between characters, or does the game end once you finish the main storyline (I don't know because I haven't finished the main story yet). or different still would it be accessed through an option on your phone? The last one I'd think would make loading times something awful.
Though all in all it sounds like a bunch of cool stuff that I'll have to check out once I beat the main and get a little spending money in my pockets again for some more games.