It definitely couldn’t have been Boomer because she was on Galactica. I suppose it could have been an 8, but I don’t remember them having any sort of revelation about that in the mini-series. That scene has played a role in the series as well - Roslyn was present that day and remembered seeing Six and Baltar together while she was dying from cancer the first time - which is how she knows that Baltar is complicit in the destruction of the Colonies. Once I found out Roslyn was in the area when Six met the mystey person I was sure she was the person who Six greeted. If not for the rumor that the final Cylon is not pictured in the “last supper” picture I’d swear up and down that she’s the final Cylon.
It could have been Eight-who-later-gets-named-Athena. They might have been planning how she was going to find a human after the attack and try to hook up with him.
I always figured that she was “talking” to the Cylon fleet that was about to commence its attack. Remember, she had been operating undercover for several years to pave the way for the attack. Once she had sent along all the information necessary to breach Colonial security she was just waiting for the rest of the Cylons to arrive and blow the bejezus out of the place.
On the day of the attack she senses that the Cylon fleet is approaching, says to the air “I was wondering when you were going to get here,” then goes to break the news to Baltar that she was a robot and he was (likely) going to die.
And the rest is history.
You make her sound like one of those Thai bar girls in another thread. 
She’s clearly going to be critical to the denouement. She does seem to be more devout in Cylon monotheism than any of the other models, more interested in the humans’ polytheism as well, more knowledgeable and in tune with the Scrolls - and, most of all, more able by far than the other models to have the Visions that I think we all know are critical. Only Boomer and De’anna have had any involvement with them at all, and not coincidentally they form the dove faction among the C’s, the ones who don’t want to destroy the humans but understand them to have a part to play in the Plan.
The note-leaver? I vote for Boomer when she was being controlled, perhaps incompletely, during “Water”.
This could be one of the tricks writers use. Put something in that allows for foreshadowing at the beginning, even if you don’t know yourself what you are foreshadowing. Later you can fill in the gaps and - voila - it looks like you had a plan all along!
There could be any number of explanations for who Six was talking to in the mini series but since it’s never been directly revealed it’s still an open ended question that can be re-examined whenever the writers feel they need to use it.
They used it once, when Roslyn was dying the first time she remembered seeing Gaius with Six. I wonder if they’ll use it again? As Roslyn approaches death this time, will her illness allow her to remember seeing a second person talking to six on that same day? Will this be how the writers reveal the final Cylon?
Exactly! There is something special about this group. They are also the ones that show the most individuality of all the Cylons.
I’d add Leoben. That guy can get in your dreams. It’s too bad Ron Moore probably isn’t going to do much with him.
I still say it was Boomer/Athena/AnEight because we had the big reveal at the end of the miniseries that one of the Cylon models was…Boomer.
-Joe
I believed it to be Boomer because she put the “Cylon” note in her own locker.
Wait, what?
Is this proven, or speculation?
Just thinking… was Boomer the only sleeper Cylon we know of besides the Final 4? And possibly the only sleeper who has other copies of her running around who know they’re Cylons? I wonder why. There were certainly other infiltrators, but all the rest of them (D’Anna, Leoben, Doral, Gina, Cavil) knew they were Cylons. Only Boomer was in the dark. Anyone have any insight into why she was singled out for the fake memory treatment? It actually seems like a bad idea, to have a Cylon sleeper agent, because of the freaking out that occurs when the person who thought he was human finds out he’s actually a Cylon.
Speculation, but I burning your speculation. How long was it between the sign in her locker and the one Adama found?
Pretty good speculation - there were lots of little things that seemed to be quite obviously Boomer’s human unconscious trying to warn her human conscious about her machine extra personality.
-Joe
What about the 6 who was raped? Did she know she was a Cylon before she was arrested? She didn’t seem to know about her model’s history with Baltar.
We saw her back story in the Razor episodes. It was pretty clear she knew she was a Cylon pre-arrest. As for her not knowing about Baltar, we do not know the mechanism by which their memories get refreshed from the other copies of their model, maybe they have to die, or be on a base ship or something.
You know it’s taken me this long to realise that Starbuck shares the same name as a well known American coffee chain.
Carry on.
I am pretty sure they were both named for the character in Moby Dick as well. But am sure someone will come by and correct me. 
Actually, the coffee company is named after the original-series Galactica character. The vaguely nautical logo was conceived under the assumption that the name was a Moby Dick reference, but it had to be explained to the company founders, who wanted a picture of a space fighter against a starry background.
True story.OK, not really.