Bracing for Disappointment

I'm currently reading the latest installment of Stephen King's Dark Tower series, entitled Song of Susannah. The series started over twenty years ago, with the publication of The Gunslinger. The series tells the tale of Roland of Gilead, the last gunslinger, and his quest for the Dark Tower. Along the way, he picks up 3 companions, and they travel along a challenge ridden path, filled with imaginative characters and landscapes. It's astoundingly ambitious, and the story has always had a teasing sort of visible potential.

Unfortunately, I've often felt that King doesn't know how to end his novels - it seems like he just makes up a bunch of compelling concepts, follows through a bit, then promptly corners himself. He sometimes manages to weasel his way out of it, but I don't generally end up satisfied. Even within the Dark Tower series, he's done some odd things (namely, the way he ended the third book - The Waste Lands - was a cliffhanger, and he didn't write the next book for 5 years). So naturally I'm a little apprehensive about the impending end of the Dark Tower series.

I read a part last night which made me feel like King knows we're not going to like it. It's a piece of dialogue between two characters (actually two personalities in the same person, but I digress), but it might as well be between King and his audience:
And remember Susannah-Mio, if you want my cooperation, you give me some straight answers.

I will, the other replied. Just don't expect to like them. Or even understand them.

What do you--

Never Mind! Gods, I never met anyone who could ask so many questions! Time is short!
Ok, so it's unfair to put those words in King's mouth like that, but that's basically how I think the rest of the series is going to go - he's going to answer a lot of the questions he brought up, but I don't expect to like them, or even understand them. It just feels like he's making it up as he's going along, and he's written himself into a corner again, with no way out. I hope I'm wrong, and I don't want to write King off completely, but if the chapter that follows the exerpt above is any indication, I'm worried.