Starbuck and Earth
We're given a new mystery at the end of season 3 with Starbuck's return. That she would return was beyond doubt. I don't think we've ever seen a major character die in circumstances anything like her supposed death and not come back. However, the real clincher was, ironically, that they took her name off the credits. Regulars on TV shows get contracts that require they be paid for every episode, whether they appear or not, and that they be credited for every episode, whether they appear or not. In order to take her name off -- to fool the fans -- they would have had to get her permission. Had she been really, most sincerely dead, that wouldn't have been asked for.
There was some debate at first as to whether she was just a vision for Apollo, but Moore has confirmed she's "real" and not just in his mind, and even more that she actually "died" in the maelstrom and has returned. Now we also must wonder about the heavy raider she chased to her death. That raider never showed up on Dradis while she showed up and then vanished. The audience saw the raider from Apollo's PoV, suggesting it was real, but Apollo himself didn't see it -- either because it was real, but not visible to him, or he just didn't notice it. But he sees Starbuck.
What she says is more interesting. She's been to Earth and back, and in a short time. And she can take "us" (presumably the fleet) there. So Earth is real, and it's close, and we're shown that with graphics as well. However, she didn't go to Earth in a Viper (she's flying a brand-new, squeaky-clean Viper) as they don't go FTL. Did she come with the Cylon fleet?
The beings who took her/rescued her appeared to her as a Cylon heavy raider, and in the form of a Leoben in her dreams. But it's interesting the first place they take her is Earth. Why would that be? To me the most obvious explanation is that they are from Earth. This may be our first encounter with Earthlings, if the Final Five are not also Earthlings. If these beings are not from Earth, do they take her there just because it is her wish? That's possible but seems less likely. And if they are not directly from Earth, they clearly know it well, and are presumably friends with the beings there. And they're cool with Starbuck taking the fleet there.
This downgrades the chances that Earth is an empty, abandoned planet. If it's empty, why rush to take Starbuck there? Nothing to see but an empty planet, in which case just give her a map, and perhaps show it to her in a virtual reality. These beings are masters of virtual reality.
Though she's real, she's something special. She is able to vanish from the Dradis, for example. In the first version of the script, she actually shows up in Lee's quarter's before he goes out, but the producers decided to go with the Viper version which didn't look so supernatural. It's interesting to think that while this implies we should not take her as supernatural, she has the non-supernatural ability, it appears, to teleport into the Galactica. As expected, the beings who took her have a much more advanced technology than the colonials or the Cylons.
One of Starbuck's other lines is "It's gonna be OK." She says this as a Cylon fleet bears down on them. She knows something we don't. This fleet is not a threat, either because they are a friendly fleet (perhaps belonging to the Final Five) or because she can protect the rag-tag fleet.