The live chat with Tamora Pierce at readergirlz has just wound down. I've managed to get in my question about Mastiff and got it answered. It seems as though we'd still have to wait some time for the novel to come out. At the moment it's on hold because Tammy is writing some stories for a collection. She's finishing Mastiff, which seems to be nearly done, afterwards and estimates the novel to be published in early 2011 (spring or summer at the latest).
I'll put the other information I got from the chat into the articles as soon as possible and will get ready for university now (it's four in the morning where I'm living). A transcript of the chat can be found here (I hope the link is working).
By the way: The Realms of the Gods as audio book as been pushed again. Its publication date is now scheduled for April 15, 2010.