A couple of thoughts:
-It has always been about three families the Starks, Targaryans and the Lannisters. The other characters/families were just puppets.
-All three families have claims to the Iron Throne, all have fought hard and experienced losses but in the end for what. There is an army on the other side of the wall that is more dangerous than anyone of these families. Can they put aside their differences, will it matter?
-As I said before Littlefinger is going to play Sansea against Jon, its about power, Jon has taken control of the North, Littlefinger is going to play Sansea, how far will it go?
-Danerys now has the Greyjoys, Tyrells and the Martlells on her side three families that have their own selfish reasons for taking the Iron Throne. The amount of colluding that will take place in that group is going to be awesome. Danerys has the dragons but in the end how are you going to keep those families happy?
-Then there is Cersi, who doesnt give two shits about anything at this point, she is the Queen and she is in control, no one has lost more in this battle and she is about to lose Jamie, she is going to go off her rocker.
-Which brings me to my next story line. Jamie Lannister. Where does he go? He isnt going to support Cersi, the Starks hate him at this point. He really has no one. And oh wait he is on Arya Starks list. This battle intrigues me. My prediction is she tries to go to Kings Landing and is caught by Cersi. Which lines her up for Trial by Combat with the Mountain, and who is that character who has loyalty to Arya and hates the Mountain? Hmmmmm.
-Samwell is obviously going to read alot of books and its pretty much the greatest day of his life since he gets to read these books. Obviously he is going to come across something that everyone needs to know specifically around the White Walkers.
My guess is that an event has to occur for the White Walkers to cross the wall and that event is going to be the pinnacle of next season.