Supposedly Drea will be able to tape both Joey and The Sopranos since they are on different shooting schedules. That being said she is the most likely candidate to get whacked, but I think she's too good a character to let go. I think Chris will find out this season that she's been an informant he's going to be torn between his love for her and his love/hate relationship with Tony.
I think the Johnny Sack/Little Carmine war will escalate and Paulie may play into that somehow. Don't forget the whole "fat comment" has yet to be linked back to Paulie and that may rear its head.