After sadly finishing the anime, I've been giving this a lot of thought, because locating others with this ability will most likely be a huge part of he second season. I'm really interested in what other people are speculating. I would have done a poll, but some of the choices would have been out-of-this-world epic (Titan Mikasa=GOD) or rather silly (Titan Armin *snickers*). But anything is possible since we know nothing as of yet!