"But the big reason I don’t give much weight to them. It would be boring. Lah-de-dah. Now if we see a lot more character development for Dee or Gaeta or somebody else, that will change my view. But if it does turn out to be her, the reaction will be, “oh. Ok, I guess it could be her.” Not. “Holy Shit!”

I predict this revelation, like Tigh/Tyrol/Anders/Foster will generate a “Holy Shit!” Anything less would not live up to the standards of the show. Actually, this is the one strike against Baltar — too many clues."

I hear what you're saying, but Joseph Adama doesn't pass this particular litmus test either. For a character who has only been talked about to show up suddenly in the last act just doesn't fly with me. It would be weak writing. However, most of the main characters seem to be too obvious a choice, and therefore anticlimactic. The reason revealing Tyrol, Anders, Foster and Tigh as four of the Final Five had such a "holy sh*t" reaction is that they weren't main characters, but they weren't minor characters either. So, who's left in that category?