WARNING: Spoilers may follow. Or disinformation put out by Ron D. Or just a load of hogwash from dubious sources.
We won't learn who the Final Fiver (heck, *the* final cylon) is for a long time -- they're going to drag that out nearly to the end.
Starbuck is the "savior" somehow, and she doesn't really know what she is. She's been to earth somehow, whether corporeal or not, they don't know.
Col. Tgh (remember, he lost the 'i' ) is pretty much in denial (which they say Hogan can play well because he doesn't want his character to be a Cylon. They said he was floored by it). However, he develops an interesting relationship with CapSix (and with Head Baltar playing it, too), trying to learn all he can about what it means to be a Cylon, and what a Final Fiver is from her as much as he can. Remember that last scene with her and Tigh? They say more of that rocking and rolling is to come.
The other Seven become divided. They don't know much about who are what the Final Five are either -- it's the stuff of legend and rumor, with different opinions. They learn about the Dylon Four, and become divided over what to do. They break down along gender lines, the boys vs. girls and have a little civil war, with one side getting boxed.
During that, it turns out that the Centurians are actually capable of sensient thought, but that ability is supressed by the humanoids to maintain control. During that fight, that ability gets turned on, and the Centurians take sides.
Whichever side prevails ultimately unboxes Xena because she knows things they need to know.
Now, as to the nature of the Final Five. It's going to be the ol' "this has all happened before, and it will happen again" thing. Apparently "Human vs Cylon" has been an eternal theme, playing out over and over again, with different actors playing different roles in the same play, etc etc. The Final Five are somehow part of the last incarnation of "Cylon", which might go back to Kobol. They are somehow the gods to the cylons in the same way the Lords of Kobol are to the humans.
And finally, Baltar. Remember a little cult, *of women* had sprung up around him. Well, he gets into full wacked-out cult leader mode (with HeadSix playing that, of course), and has a harem of all his devoted female followers. Don't you just hate him? If you thought that little Menage-a-Psychosis with Xena and CapSix was something, you ain't seen nothing yet.
*****Big time spoiler, if true: DOUBLE WARNING************
Cally blows her brains out when she learns the Chief is a Cylon.
Whether any of this is true, I don't know, but that's the current rumor mill.