The books are absolutely jam-packed with detail, foreshadowing, reference and masterful writing (have you noticed Felurian speaks in Iambic pentameter?). I think he has just written himself into a combinatorial explosion of a corner.
Kingkiller is like the Lost of epic fantasy: at first you're drawn in by all the detail and mystique, but later you realize that he's just making it up as he goes. It's super easy to open compelling and interesting threads (e.g. what is the smoke monster and who are the Chandrian) but its much, much harder to close them.
