In the last episodes of BSG we see Baltar and 6 walking in our present days and observing.
Who are they? Why do they look exactly like the original two? And why do they seem to know the "real story" of humanity as opposed to anyone else?
Quotes from Daybreak Part 2
Virtual Six: Commercialism, decadence, technology run amok. Remind you of anything?
Virtual Baltar: Take your pick. Kobol. Earth... the real Earth, before this one. Caprica before the fall.
Virtual Six: All of this has happened before.
Virtual Baltar: But the question remains, does all of this have to happen again?
Virtual Six: This time I bet no.
Virtual Baltar: [Stops] You know, I've never known you to play the optimist. Why the change of heart?
Virtual Six: Mathematics. Law of averages. Let a complex system repeat itself long enough and eventually something surprising might occur. That, too, is in God's plan.
Virtual Baltar: [Serious] You know it doesn't like that name.
[Six gives Baltar a defiant look] Silly me. Silly, silly me.
[The two walk arm-in-arm off into the streets.]