Right, this one lost its head fast.
So anyway.
First thing's first -- if you're going to adapt the story you gotta figure out what in the hell the story is. As we discuss in the GREEN MILE commentary, the way King rolls is just to start writing and see what happens. So what you tend to end up with is a GREAT premise with really weird, wild, and out-there characters and concepts populating the world, and which ultimately go kind of nowhere. King writes well (or at least did, I haven't read anything since Cell) so his books, sentence-by-sentence, are engaging and enjoyable. But if you're expecting a point -- or even a decent ending -- you're shit out of luck often as not.
Of course, the interpretation of what the story is "about" is always the director's job -- it's what used to be meant by the director's "vision" for a film, before most directors actually started dictating the visual style itself. So if you ask my vision for Dark Tower, I've got three bullet points:
1) The broad theme of the story -- what the entire story is about -- is the importance of imagination. When all we had for nearly a decade was the first four books and were trying to sort out what was going on, I settled on the idea that Midworld, where the Tower stands, is the world of fantasy. That the Tower, in fact, IS human imagination, connecting all worlds of human fantasy together. But people are losing their sense of wonder and fantasy for the cold world of technology and mindless consumerism ("the world has moved on," technologies literally gone mad like the Beam Guardians and Blaine, one of the only remaining societies being the Luddites), and the Tower is falling. This is why other worlds of fantasy start to encroach on Mid-world -- why the Emerald City appears in their path, why the Wolves of the Calla look like Dr. Doom. Roland has to save the Tower, to save his world and, really, ours as well. Astute film fans may realize that this is also what THE NEVERENDING STORY is about.
2) Roland's arc is about learning to care about others. He's so focused on saving the Tower, saving all possible worlds, that he's forgotten what and who he's saving it for. On several occasions he will abandon someone he loves for the sake of the Tower. Only when he makes the opposite choice does he become worthy of finally getting there.
3) Salvage anything in books 5, 6, and 7 that help to tell at least one of those two stories and nuke the rest from orbit.
Because we have the benefit of having the whole series laid out before us, unlike POTTER, I would in fact want to write the entire series in adaptation form before a frame was shot. Dealing with Jake, as you point out, I would want to shoot everything with youngest-Jake, even stuff that wouldn't show up until far down the series, all at once, and otherwise shoot as chronologically as would be feasible.
How I would execute it... I don't know. I'd probably do the first four stories in the order we got them, so WIZARD AND GLASS would be the fourth film, not the first. My guess is that they are planning to do it the same way.
The talk of interweaving films and TV seasons has some appeal, especially in the light of such a successfully executed adaptation in GAME OF THRONES; though honestly I think if the films were allowed to be 3 hours you could do about a book per film and probably not lose too much (and probably not even need 3 for GUNSLINGER). Much would probably depend on the alternate second half that would have to be developed -- could be there's only a need for one film after W&G instead of three.
