Ripped from WotW:

Let the casting speculation begin!

The first role on the table is…

Pirate, man in his 40’s to late 50’s. He’s “an infamous pirate who has terrorized seas all around the world. Cunning, ruthless, with a touch of madness.”

He’s a dangerous-looking man. A very good part this season.

We’d heard unconfirmed rumors that Theon’s uncle Euron Greyjoy would be appearing in season 6, and this sounds like him, more than his brother Victarion.

Next up is the one I’m personally most excited about:

Father. Aged 50’s to 60’s, he’s one of the greatest soldiers in Westeros- a humorless martinet, severe and intimidating. He demands martial discipline in the field and in his home. It’s described as “a very good part” for next year and that he’s “centrally involved” in a protagonist’s storyline.

This is a clear description of Randyll Tarly, Sam’s abusive father and the famous soldier mentioned by Stannis Baratheon this a couple episodes ago. Some had guessed the discussion might mean we’re seeing him next year, and they were right.

The next three characters appear to be linked to this storyline- most likely Sam’s mother, brother Dickon and one of his sisters. All have the same comment about being centrally involved in a protagonist’s storyline.

Mother, in her 50’s. She’s a sweet, plump, and adoring mother, and has a soft spot for one of her children who benefits from her decency.

Sister, in her early 20s. She’s a kind, friendly and unpretentious woman.

Brother, in his early to mid-20’s . Athletic, a good hunter, an excellent swordsman, manly, not particularly bright but the favourite child of the father.

Next up:

Priest, in his 40’s or 50’s. A gruff ex-soldier who found religion. Now a no-nonsense rural priest who ministers to the poor of the countryside. He’s salt-of-the-earth man who has weathered many battles.

Sounds like Septon Meribald, although it’s a little surprising we’d see him next year instead of this year. If it is him, that hints at someone surviving the season.

A few more roles:

Leading Actress, in her early 40’s, she’s an elegant actress with a traveling theatre company. Fun, charismatic, rum-drinking actress in the troupe.

Priestess. Mid-20’s to early 30’s. Any ethnicity- she’s beautiful, intense, and magnetic.

Fierce Warrior, a tall man in 30’s or 40’s with a powerful physique. They’re looking for someone with “mixed ethnicity” for the role.

They’re also searching for a trio of young boys with very specific descriptions. My instinct says another flashback- perhaps this time via the weirwood network?

A large boy, with an actor who is 10-12 but playing 7 or 8. He’s described as “a clever boy” who seems too large for his age. He’s big and tall but not fat. “Characterful squat features” are a plus for this part. it’s specified that this is a one-time appearance.

12 year old boy, with brown hair and blue eyes. He needs to use a Northern accent. He has scenes where he has to spar with a wooden sword.

The length of the role isn’t specified.

7 year old boy with dark brown hair, a narrow face and green eyes. He also has a Northern accent. He also spars with the wooden sword, so it’s safe to assume it’s the same scene. This role is similarly open-ended, the description only stating that the character is being ‘introduced.’

It’s worth noting that Sean Bean has green eyes, so if this is for a flashback role, the write-up would be a good fit for a child Ned.