Cylon Theory
I must digress into a bit of Battlestar Galactica geekyness here. I love the re-imagined series - it’s the best thing on T.V. that doesn’t involve racing. There is a mystery involving the identity of the final Cylon, and here is my take on that, and Cylon theory in general.

So anyway, I think this, Battlestar Galactica’s final season, is all a set up for the backstory driven “Caprica” series scheduled to be piloted this Fall. It is my belief that the basis of the conflict between humans, the Significant 7 and the Final 5 is all tied back to the creation of the Cylons themselves. From what we understand, the Adama’s and the Greystone’s will be the prominent families in Caprica, and I think the Cylon factions we see now represent the differing philosophies these families had when creating the Cylons. That’s right, I think the Adama’s and Greystone’s were either the creators of, or had a significant hand in the legislation that brought about the Cylons. Of course, there had to be some conflict, some philosophical difference between how these two families viewed Cylons, artificial intelligence in general and automatons and free will. It is easy to imagine a camp who believed that the Cylons were designed simply to serve (hence the “one God” monotheism held by the Significant 7), and another camp who saw them as living creatures, an evolutionary step entitled to rights and maybe even citizenship. I think the latter would be represented in the Final 5, or at least the four we have seen. The last remaining Cylon - who knows. That may be reserved for a clone of the creator of that line. We’ll see.
I think this explains how these Cylons are so different. The Final 5 that have been revealed seem to be inherently more human, more flawed and susseptible to illness. There is no philosophical quest driving them, at least to this point. The Significant 7, on the other hand, are obsessed with things that are inherently human - procreation, religeous ponderings, and what it is to “feel” something. Much, much more primative. Of the final 5 we have seen, they have demonstrated a bredth of human emotions - love, grief, hope, fear. There is little doubt that they are more evolved, or at least more “human” than the other Cylons.
So the conflict, the idea that the significant 7 can’t think or talk about the Final 5 makes sense if it was a programmed aversion, placed there by a creator who is a rival of the Final 5 creator. This means, I suspect, that the conclusion of BSG is also the culmination of another series, Caprica, with the family rivalry getting it’s final play in the quest for Earth.
Back to this idea of who is the final Cylon, I dunno. Whoever it is, I think there is another layer to it. For instance, if it were Doc Coddle, he is probably more than simply Doc Coddle. He is probably tied to the actual creation of the final 5. Or if it is Baltar, I like the idea that he programmed his own ignorance and that the 6 in his head is really a manifestation of his own guiding subconciousness, pre-programmed by him years prior. Maybe it IS an Adama, but not Lee, Zack or William… rather Grandpa Adama, perhaps the creator of the Final 5 Cylons themselves. If the Adama’s are in some way responsible for the whole Cylon mess, well, can you say “redemption”?