Let the man write at his own pace. It will come out when it's out.
Honestly, I can't stand it whenever I see an article about him at some convention and the comments usually consist of people complaining about the books not being finished. I don't think those kinds of folk understand how difficult writing can be at times, especially if there are other things in your life that are keeping you busy. I'd rather he take his time with the book than rush it out and cater to fan demand; that's how quality suffers and shitty stories are produced.