Thus far in its run, the person who sits on the Iron Throne has been a cause of great concern. King Robert was killed, thanks to the scheming ways of his wife Cersei, and Joffrey installed as the new ruler of the Seven Kingdoms. However, Robert's death greatly upset the balance of power in Westeros, which hadn't exactly been stable anyway, and led to the War of the Five Kings.
Since then the question of just who will ultimately on the Iron Throne has been poured over again and again by fans (it's probably not going to be Cersei, even if she is the current occupant). Was/is Stannis the rightful heir? (Yes.) Should it really have been Joffrey, and then Tommen? (No, it shouldn't.) Is it eventually going to be Jon, or Daenerys, or Sansa, or someone else ruling Westeros in the end? (Maybe.)
9. The Kingdoms Will Be Truly Divided
Rather than one King or Queen ruling Westeros from the base of King's Landing, perhaps what is truly needed in order to restore peace and prosperity to the land is for some proper devolution of powers (are you listening, Theresa May? No, probably not).
This fits in with the Great Northern Conspiracy, which states that Robb Stark left a will in which he legitimises Jon Snow and names him as heir to Winterfell and the North. A group of Northern Lords are well aware of this, and are working together in order to see the plan come to fruition, with Jon becoming the King of the North as a truly separate state. It's something we've already seen start to play out on the show, with Jon KING IN THE NORTH, but it could always go further.
Going even further back than Robb's demise, even before Robert's Rebellion, there was the notion of the Lords of the North, the Vale, and the Riverlands all working together to overthrow the rule of the Mad King Aerys II Targaryen, and gain more power from their own lands.