This story contains potential MAJOR SPOILERS for the final episodes of “Battlestar Galactica,” along with the possible identity of the final Cylon. It’s been one of the best kept secrets in science-fiction fandom: Who is the 12th and final Cylon, and when will it be revealed? Sources have told SyFy Portal in the past that the final Cylon’s identity was originally intended to be revealed in the mid-season finale of SciFi Channel’s “Battlestar Galactica” that aired earlier this year, but that storyline was pushed into the early episodes of the final batch of shows that premiere Jan. 16. Speculation has run rampant through both fandom, and even some of its celebrity followers like director Kevin Smith and author Peter David. But several sources have revealed the identity of the final Cylon …