If the info is truth... if it is someone from season one and the person is dead. I think the final cylon would have to be Captain Louanne 'Kat' Katraine. In the last episode before the break. when they finally reached "earth" I recall Starbuck starring at Kat's picture in the halls. Personally, why whould they even bother with that scene if not to remind us of Kat.
I think that shot of the memorial hall was supposed to represent all the people who didnt make it to Earth.