Sup guys. Yeah, I've pretty much been busy being an OT.com hermit the last 9 months. Long story short, other things have been more important uses of my time. I'll probably be jumping back into the game in the next month or so.
Anyway, as far as any permissions go, personally I think it's cool people care enough to do this, although on the flip side I don't think audio-books are suited to anything like this (e.g. academic books). My publisher might not be as nice about this, but I can pretty much guarantee you that my publisher would never even consider an audio book, so it's not like any business would be lost. I guess the only concern would be over the quality. That would be my main concern too, because it's hard for to envision an audio version of this book that isn't boring, but maybe I lack imagination.
I think the main thing though is that I am knee-deep into the second edition of the book. The core of the book would be the same, but I imagine about 15% would be altered or changed. I don't know if this would actually end up changing the project timeline here, or if it would get me into trouble if I were to hand out the updated manuscript to anyone involved (probably it would), but it may be worth mentioning. Off the record, the second edition manuscript is due from me at the end of July for a print date for February 2013.
Otherwise, hey, if we asked permission for anything we did here we might as well not have this forum at all. The world of fandom will do what it wants.