With so much chaos, gloom and misery in the world, what better time to consider the unbearably close advent of Battlestar Galactica's return, in which we'll find out exactly how we managed to destroy Earth. With all the half-baked theories flying around, I thought I'd confess my own quarter-baked hypothesis on the womanity of the Final Cylon. Feel free to offer your own baking. That is, if you are some kind of ridiculous geek, which of course you aren't.
1. I get the feeling that the 12 Cylon models should symbolically correspond to the 12 gods of Kobol - ie the Greek Olympian Pantheon, of which seven are male and five are female. So far we have seven male Cylons and only four female. Thus, the Final Cylon must be an incarnation of one of the female characters. To increase the feministy credibility of this post, please feel free to discuss the gendered implications of the archetypes of the Olympian Pantheon as compared with the personality traits of the known Cylon models.
2. Also, even if this light baking doesn't fly, you just wouldn't have eight male and four female Cyclons. It's too unbalanced.
3. D'Anna indicated that the Final Cylon was 'not in the fleet' upon her unboxing. From this, one could guess that the Final Cylon could be either Roslin, Boomer, one of the Sixes that is of any interest (but not Caprica Six in the Galactica brig), or some other original or Ur-version of Starbuck (because that is totally not the original Starbuck.)
4. Spoilers indicate that the 'Last Supper' image is way more obvious than everyone thought.
Thus, my punt is Head Six FTW! This rests on the assumption that the Final Five Cylons are beyond fixed physical incarnations in eg. model types, that their consciousness gets transmitted in some other kind of way (Like a virus or transmission?) and that Head Six, the Six in Baltar's head, has some esoteric God-y connection to the original Creation that explains why she's the robot Jesus of the ether.
Okay, you really did not need to read this.