The list only contains some brief descriptions, so for those who haven’t read the books, this will only scratch the surface. Here’s the list:
Mance Rayder: We’ve heard about him all season. A former member of the Night’s Watch who became the “King Beyond the Wall,” the leader of the Wildlings.
Daario Naharis: A confident and seductive warrior.
Jojen Reed; Meera Reed: A teenage brother and sister duo with special insights.
Edmure Tully: A brash young member of the Tully family.
Ser Brynden Tully (The Blackfish): Catelyn Stark’s uncle.
Lady Selyse Florent: Stannis Baratheon’s wife.
Shireen: Stannis’ daughter.
Olenna Redwyne (The Queen of Thorns): Margaery Tyrell’s sharp-witted grandmother.
Beric Dondarrion: A skilled knight who is the leader of the outlaw group Brotherhood Without Banners.
Thoros of Myr: A red priest who follows the same religion as Melisandre.
Tormund Giantsbane: A Wildling raider.
This list comes straight from showrunners David Benioff and Dan Weiss, and they point out that there are even more characters from the book not listed here that are likely to show up in the third season as well. However, for those worried about having too many characters to follow on an already crowded series, Benioff and Weiss say,
“It’s important to point out that that we have the largest cast on television right now. We introduced dozens of new characters in season two. If you hurl 300 characters at an audience, the story collapses under the weight of too many faces, too many names, and too many subplots. We need to be just as mindful of the audience members who have never read the books as we are of the readers; the series will fail if we only appeal to those who already know the characters. So we try to be parsimonious about how many new roles we introduce to the story and when we introduce them.”
So while there will be plenty of characters in the mix, we may not see all of them often enough to make the season feel crowded. Either way, there’s going to be a lot going on next season, so it’s clear why the third book is being split into two separate seasons.