Okay, I actually went to three things at Readercon; this was the last. As it was a discussion, I didn't take many notes; and since work is going fairly well, I think I can spare a few minutes to type up my few notes while they're fresh (and while I'm waiting for the Advil to kick in. Boo, headaches.).
Short non-spoilered version: There were only six people in the audience, and one of them, well, I had to say at one point, "Excuse me, I wasn't finished talking." Despite, or because of, that John Langan did a nice job as moderator. No-one really had answers for my questions, but a few interesting points were brought up for me to ponder in other areas.
Here's the spoiler version. If you haven't read the books, it won't make any sense; and if you might read the books, it will ruin things for you.
SPOILERS start below the blank lines.
Someone mentioned the frequent maiming of Roland, which sparked a thought in my mind of whether his physical reduction parallels, or even drives, his moral and emotional growth. I will have to look for this on that re-read that I am going to do, honest, really!
Langan pointed out King's obsession with the law-man figure (almost always a man) throughout his works, which culminates or is encapsulated by the DT series. Is King really a Western writer rather than a horror writer? (This goes back to a comment at a panel of yesterday, that I will write up later, about some genres being subject matter, and others being effect; so I'm not sure it's an either-or choice between Western and horror.) Later he pointed out that the battles all stay on the Western model rather than the epic fantasy model.
Langan brought up the Wizard of Oz and the humbug behind the curtain, which is apparently also a big part of Pet Semetary, which I haven't read. He suggested this is a pervasive anxiety of King's.
Langan was also interested in the way pop-culture became increasingly more prominent in the series. He mentioned an early novel by Delany, The Einstein Intersection, which also referred to "darkle" and "tinct," and is apparently about far-future aliens who are re-enacting human mythology, and wondered if there was any influence on the Dark Tower series.
There was some discussion of the anti-climactic nature of the Crimson King and of Randall Flagg, both in their appearances in book 7 and in their ends. (Have I mentioned before that I found Mordred disappointing? Well, I did.) Langan suggested that the epic fantasy form may have pressured the Crimson King into being the big villain, but that it doesn't work well because all his scariness is left in Insomnia and isn't present here. To my recollection, it seems that the enemy, or the threat, to the universe shifts somewhat over the series, so I'll need to re-read for that as well. He's explicitly not a threat to the Tower after they've saved the Beams, unless he gets his hands on one of Roland's guns, but before then? (And what does the comparison of the Crimson King's appearance to Santa Claus suggest?)
Also, there's all that eye imagery, which the discussion noted and didn't quite know what to make of. The loud person suggested it was a "blessed are those who believe but have not seen" kind of thing, which might tie into the anti-technological theme ("Use the Force, Luke!").
(No-one else had noticed that Roland didn't have either of his guns when he went into the Tower—several people tried to tell me I was wrong, in fact—so no-one could answer me how he got into the Tower in the first place. My complaint that the Universe is putting itself in peril over and over again just to fix Roland, seemed also to be new to those there.)
Oh, and hey, I got thanked in the program for the suggestion of this discussion! I am unreasonably chuffed by this.