Okay, in DT 7, right after King gets hit by the minivan, Roland tells him to return to the path of the Turtle, to finish the tale.
King mentions The Path Of The Bear also, and Roland is confused.
I take this as further proof that the series is not finished. I believe he intends to expand the whole series, perhaps adding more novels.
I, for one, would like to see all seven books rewritten, from the perspective of another level of the Tower; Jake lives, major events are replayed with alternative outcomes.
And then, as a career finale he writes five new Tower novels, for a total of 19 books.