Not gonna be good
For a start they’ve got Josh Boone writing and directing, which going by this man’s track record is not a great choice for the story. The only stuff he’s made before this is syrupy soap opera fluff.
Secondly, a lot of the casting is all wrong. It doesn’t matter to me that Larry Underwood is played by a black actor, his ethnicity is mostly irrelevant in the novel, but the actor playing the part just doesn’t exude the egotistic, selfish confidence that the character had in the novel. The actor is too young and feels more like a Nick Andros type.
And Skarsgard as Flagg is such an uninspired choice. Do we really need this guy to play every King villain? He’s not even intimidating. Nor do I believe he has the charisma to lead an entire legion of followers to rebuild the country. I would picture an actor with more menace to them like Hugo Weaving, or even Garrett Dillahunt.
Thirdly, this series is obviously going to be set in the present day, which is a mistake. The original book was set in 1980, and most of its atmosphere and dread comes from the Cold War paranoia of the era, as well as Mother Abigail’s connection with the 19th century. Moving it to the present day makes it lose a lot of its power, as the best King adaptations are period pieces, or were at least filmed roughly around the same time as the book was released.