I'm going to have to say the Final Cylon is Dualla.
Why?
Well, first of all, "Anastasia", her first name, means "resurrection". We've seen another character with a name with the same meaning. Gina's last name meant "resurrection" in Old Gemenese.
Second, look at the other members of the Final Five: Tigh is XO and a close friend to Adama, Tyrol was the Deck Chief and union leader, Anders is a former celebrity, two-time resistance leader, and married to Kara Thrace and Her Special Destiny, and Tory is the aide to the President.
Except that she wasn't always that. For the first season and a half, that was Billy's job. Who dated him? Dualla. How did Tory get the job? Billy was killed shortly after Dualla rejected his proposal, and spent the evening with the CAG of
Galactica. Said CAG, the Admiral's son, is made CO of
Pegasus, and she is eventually made her XO.
Then Lee used
Pegasus as a battering ram and became a lawyer. She dropped him like a hot potato.
Also, note that she's never very far from Gaeta, especially during some of his big frakups. The exception is the fixing of the election, where she worked with Tigh on a plan created by Tory.
As for Earth, I'm probably the only one who thinks that Starbuck
and the Hybrids are right. Think about it: the Lords of Kobol are similar to, and in fact have many of the same members as the Olympians, of which there are twelve at any one time. Presumably, the Twelve Tribes, at least on Kobol, formed from the people who dedicated themselves to a particular Lord.
Except there are Thirteen Tribes.
There are hints that the unspecified disaster that forced the exodus from Kobol was actually a war. It was outright stated by Elosha in a deleted scene. While such a scene isn't canon, it is reinforced by Roslin's comments after Baltar's interrogation. The pillars in the Temple of Five are fashioned after the five priests dedicated to "The One Whose Name Cannot Be Spoken".
Why does Roslin's comment reinforce Elosha's? Let's assume that the Thirteenth Tribe, dedicated to the Thirteenth Lord of Kobol, decided that their particular Lord should be worshiped above all others. A holy war begins. The Thirteenth Tribe loses, and flee/are banished, heading for Earth. The war leaves Kobol uninhabitable, and the other Tribes leave in a different direction, becoming the Twelve Colonies.
How do the Colonials deal with the war? They strike the name of the Thirteenth Tribe's patron Lord from their religion.
How does the Thirteenth Tribe's religion change? If they didn't before the war, they begin to refer to their patron Lord as "The One True God."
Millennia later, someone from Earth finds the Colonies or the Cylons. If they found the Colonies, they infiltrate and either create or corrupt the original Cylons, leading to the first war. If they found the Cylons, they give them the technology they have at the start of the miniseries. Either way, the Thirteenth Tribe gives the Cylons their religion, in a ploy to get them to do the dirty work in settling a four thousand year old grudge.
Long story short, Starbuck knows where Earth is, and, as the Hybrid said, leading the Colonials there will lead them to their doom.
Or
Galactica could make it to Earth... after trading in the refugee fleet for an armada of Basestars determined take down the Thirteenth Tribe.
Hey, it's better than what oBSG did.