Arya is really one of the characters whose development I'm most curious about. I mean, I love people like Stannis or Davos, but I don't really see them changing radically (unless GRRM goes for Nightking!Stannis, which I really don't hope for). And I see people like Tyrion and Daenerys changing a lot, but I don't really -care- much about them, emotionally. But with Arya, I'm really, really curious about what GRRM has in store for her. I think it all depends on how and when and under what circumstances she rejoins the other characters, and whom she meets again.