I've owned the kindle version of this book for ages, but hadn't gotten to it yet. Voila - with the audio upgrade program, for a few bucks more, I have the audiobook and am listening to it at work.
It is lovely, so far. Kathryn Kellgren - who narrated Mina Harker's part in Dracula - is fantastic and audio is the perfect way to experience this book because it is told as a series of journal entries, so I feel like Morwenna is talking directly to me.
I am also just loving the references to classic science fiction and fantasy. Morwenna is an avid reader whose love of novels is her lifeline and the prism through which she sees the world. Jo Walton's blog has a bibliography available here (listed by author).