On the "Talking Sopranos" podcast, Imperioli revealed that Liotta is playing "Hollywood" Dick Moltisanti, a previously unmentioned character, Dickie's father and Chris' grandfather. I think they are doing a bit of a retcon here with him and Livia being brother and sister as well. They still haven't said who Joey Diaz is playing, but I'm going to have to assume that he's Big Pussy's father or uncle, some relation. Young Puss is sitting next to Paulie in the car in the trailer too, btw.