Dragonstone: That the question of Varys’s loyalties comes into question makes sense (and the question is raised with some references to lines from A Game of Thrones, no less, in regards to Illyrio’s claims of the support Viserys would receive), and very much follows the novels. While he claims to various individuals that his concern is the good of the realm, his actions seem quite contradictory to developing a straightforward path to the realm’s good. Although Missandei’s technical vocabulary seems a little too much in the scene, what she says about the grammatical gender of the Valyrian word for prince is true to the novels as well. Finally, we know we’ll see Casterly Rock in the novels—GRRM has said so.
The Citadel: It’s in keeping with the novels that children can sometimes survive greyscale with only disfiguration. It is inevitably fatal in adults if it begins to spread, though.
Winterfell: The realization of the value of the dragonglass on Dragonstone is something already present in the novels.
Possible Developments in Future Books
Dragonstone: Can’t be ruled out that there’ll be summons and meetings between rival claimants in later novels.
Winterfell: Someone realizing that the dragons might be useful against the wights and Others is bound to happen.
King’s Landing: The foreign nature of much of Dany’s supporters will likely be one reason she does not find Westeros as entirely welcoming as she may have hoped.
The Riverlands: Hard to imagine that Arya will never go to the North again… and it feels like her having a chance encounter (or perhaps not so chance, given her skinchanging) with her old friend Nymeria could fit Martin’s plans as well.
Entirely Different
Dragonstone: Varys’s failure to respond to Dany’s wondering why he thought Viserys would be a good king seems to be the writers admitting that they have no real solution. In the novels, the key issue is that neither Viserys nor Daenerys was ever intended to become the ultimate ruler—instead, they were stalking horses for another claimant to the throne. As noted in previous seasons, Missandei is very much aged up from the novels, so I wouldn’t expect a romance to develop with Grey Worm in the books.
King’s Landing: Randyll Tarly’s a Tyrell bannerman first, a subject of the Iron Throne second. This is a very different depiction of the character and I’m dubious that the murders of Mace, Margaery, and Loras would create such a change. Qyburn’s idea of a giant crossbow to kill dragons being motivated by Meereen is silly—a scorpion bolt killed one of the three great dragons, Meraxes, during Aegon’s attempt to conqueor Dorne.
The Citadel: As noted previously, Jorah does not have greyscale in the novels. There’s also no way that there’s some secret cure to greyscale in the Citadel. The “Ch’vyalthan” name, allegedly of some maester, remains as horrible and out of place in Westeros as ever.
Winterfell: It doesn’t feel likely that the novels will put Jon and Sansa in the exact same positions as on the show, so their interactions regarding the rule of the North and Winterfell seem like part of the show’s major streamlining.
At Sea: This entire sequence in which Euron murders or captures Sand Snakes and Ellaria Sand won’t be happening in the books.