With FFI, II, III, VIII, IX, and X's rosters fully confirmed, there's only room for three more games. FFVII's Sephiroth has been teased in trailers for the longest time, and 1UP's preview also mentions that FFVI's Kefka had been spotted in a new trailer at the recent Square Enix party. This basically points to both VI and VII being confirmed for two of the final three slots. That leaves either IV or V to be cut from the game. Seeing as V is the worst title in the series (feel free to send us your hate mail), most likely it'll be the one to be cut.