Is there any one who is a fan of author Garth Nix and his Abhorsen Trilogy?

Please! I have heard rumor of a fourth novel from the Old Kingdom. Titled Clariel: The Lost Abhorsen. I am trying to find out if this is true! I love his Abhorsen Trilogy and have looked forward to a new book. I've looked at his website. His facebook page. The Amazon author page but, I've seen not tell tale sign that there is a new book on the way. If any one can help me out I will absolutely appreciate it! Thank you!