Samwell: Sam and Gilly do travel by sea toward Oldtown, as depicted, with Gilly’s child. Samwell also intends to visit Horn Hill to leave Gilly and her child in the care of his family, as they discuss.
Bran: The Tower of Joy sequence is somewhat inspired by Eddard’s fever dream in A Game of Thrones. In particular, in the novels Eddard noted to his son that he would have been killed by Ser Arthur Dayne if it were it not for Howland Reed.
Meereen: Astapor and Yunkai ultimately acting against Daenerys and Meereen are features of A Dance with Dragons, although Astapor requires an invading army to wipe out its ruler King Cleon. Tyrion apparently intends to negotiate towards peace with the other cities arrayed against Meereen, which is largely what Hizdahr zo Loraq does following his marriage to Daenerys in A Dance with Dragons.
King’s Landing: Cersei does make extensive use of Qyburn as a spymaster, and shows particularly interest in the actions of supposed enemies. The tensions between Cersei and some of the notable members of the small council are also drawn from the novels.
Braavos: Arya’s training—especially the lying game with the waif and the study of poisons—are largely drawn from the novels. Although the timing is changed, Arya’s vision is indeed restored in the novels after a certain amount of time passes.
Possible Developments in Future Books
The Wall: If Jon returns as expected by many readers it’s likely that some sort of justice will be meted out to at least some of the conspirators. It’s also a popular speculation that his death will allow Jon—or others on his behalf—to argue that he has fulfilled his vows, and is no longer a member of the Night’s Watch.
Tower of Joy: It’s possible that Bran will somehow witness the events through his weirwood visions, although so far they are restricted to places within sight of weirwoods.
Daenerys: It seems quite possible that Daenerys might go as far as Vaes Dothrak as part of her journey as prophesised by Quaithe of the Shadow, who states “to go forward, you must go back.” However, given the circumstances at the end of A Dance with Dragons, it’s difficult to imagine the circumstance in which she would face being forced to become a member of the dosh khaleen against her own will; a person with a huge dragon at her side would likely have some say in the matter.
Bran: The show streamlines the conflict at the tower of joy—famously, Ned says he and his companions numbered seven, and faced three men, but on the show it’s now six versus two. Further, Ser Arthur Dayne takes the most prominent speaking role, whereas in the novel it’s the lord commander, Ser Gerold Hightower. The details of the fight have never been revealed, but we do know that Ser Arthur used his greatsword Dawn, not two swords (although one of them, a hand-and-a-half sword with a sort of setting sun motify on the pommel, is probably supposed to be that famous blade). The dialog has been pared down as well, compared to the novel. Finally, in the novel Bran is aware that Ned would have been killed by the Sword of the Morning without Howland Reed’s intervention, but on the show it seems to be implied that he was unaware of the fact that his father was outmatched. It’s also worth noting that on the show, Ned Stark is supposed to be a much better swordsman than the character in the novels, who was proficient but not exceptional. The three-eyed raven claims to have been in the weriwood for a thousand years, whereas the three-eyed crow of the novel can’t have been there for more than a few decades, suggesting they have very different histories.
King’s Landing: The open way in which Ser Robert Strong is acknowledged to be Ser Gregor Clegane is a stark difference from the novels, where some characters may suspect the fact but are unwilling to discuss it. Qyburn does not have access to Varys’s “little birds” in the novels—far from it, in fact, given their role in events in A Dance with Dragons.
Braavos: Arya’s list is rather short on the show compared to that of the character in the novels.
The North: Assuming Lord Umber is essentially the Smalljon, he is radically different from the character in the novel, who died trying to defend Robb Stark at the Red Wedding. The death of the Greatjon is part of the show’s streamlining, as he remains alive (but a prisoner) in the novels. At the same time, this disloyal Lord Umber would seem to play more at the role of the Umber uncles, who appear more diffident in their loyalties. Finally, at the end of A Dance with Dragons, Shaggydog is very much alive on the isle of Skagos, and it’s probable Rickon and Osha have found refuge there.