The end is in sight. The end of the fourth book, anyway.
With Wizard and Glass, King is telling a flashback, the long, very long telling of the story of Roland's long-gone first love Susan. After Roland became a gunslinger, he and two friends were sent away by Roland's father to a far off village where they found strange goigns-on that threaten their homeland. Roland also finds his first love with Susan Delgado, who has "sold" to the local mayor as a consort, since his wife is barren, alas.
King has dropped enough hints about Susan that we know that it will not end well. With about 150 pages to go, Roland's and Susan's illicit liasons have been revealed, and Roland and his friends have been captured, framed for the murder of the mayor, who was actually killed by the dark forces that have infiltrated the town.
This is the first book of the series when I started to think that King was padding things a bit. Mind you, padded King is better than many authors' tight prose, so that's not much of a complaint.