Yeah that's one of my questions, what happens to Tyrion? He is the heir to Casterly Rock, with Jamie being in the Kingsguard. He could also arguably rule Winterfell, being married to Sansa (although I think that marriage will end - I think her future is intertwined with The Hound in some way). The smarter money is on Rickon eventually being the Lord of Winterfell. And Arya is being trained to be an assassin - so she has a major role to play in the end too. Who is she being trained to kill? My money's on Cersei, but that just seems too easy and one thing GRRM isn't, is easy to foresee! So what happens to Jamie and Brienne? And where do Stannis and Theon play into everything? Oh, so many questions! Only two books to go - they are gonna be good ones!