Yes, they are. Ron Moore clears up BSG's season finale
Battlestar Galactica executive producer Ron Moore answered a few questions from a reporter at Pittsburgh's Post-Gazette that clear up some of the confusion from last night. For instance? Yes, they are Cylons. Chief, Saul, Sam and Tori heard the music when they reached a certain point in space, signaling their awareness of who they are. Moore says, "These are four of the final five, which puts them in a separate category from everybody else." Who is Cylon #5? Moore doesn't say. But he does promise that, next season, we'll get to discover the backstory for the new Cylons as they try to figure out how this could happen.
While he does clear up the Are-They-or-Aren't-They mystery, he doesn't say anything revealing about Starbuck's return. Is she a hallucination? A Cylon? Moore says, "It's exactly the kind of thing I want people to chew over the next few months" ("Few"?!? Season 4 doesn't start 'til January!). Katee Sackhoff, who plays Starbuck, is signed on for the next season.
He also reveals quite a bit about why Roslin's cancer has returned. It is, he says, to fulfill the prophecy that "a dying leader" will get them near the promised land but will not survive to see it herself. Why does Roslin communicate with the other Cylons through visions? No answer there.
That's all we learn about the finale.
As for the movie that's coming out in the fall, Moore describes it as "just a couple of extra episodes for the fourth season that will air earlier than the rest of the season." It is, he confirms, about the Pegasus and Admiral Cain. But, he says, it also sets up one storyline for the next season. "It's an opportunity to set up something for the fourth season that had not been told to the audience and that the characters themselves had not realized."