I've been into the Dark Tower series for about a little more than a year, maybe, and I'm still on Wolves of the Calla (Book V). I've always been a big Stephen King fan, and I love how he's incorporating a hellovalot of his other works in with this one ... I'll be reading along, and be like "wait a minute!". Good stuff. I don't know if I can NOT read the last two, though ... I'll get to 'em.

HUGE (SPOILER) I've heard in the last book, the ka-tet actually MEETS Stephen King. Like, as if they've come to our world and are meeting him. Weird.