Two things:
First: Has anyone else besides me noticed that the name "Little Mouse" (Rowl's name for Bridget) is an obvious nod to Dresden's dog "Mouse". The dog who was small enough to fit in a pocket but became a huge monster of a dog upon adulthood. (Bridget is an unusually tall girl.)
The etherialsts: I see them as this world's version of a wizard. Anyone else see any other parallels?