The Meowmorphosis (Quirk Books, 2011) by Franz Kafka and Coleridge Cook, here. Is it the "death-siren of mash up fiction"? Some reviews here, here, here, here. Some selections here.
& Leo Tolstoy & Ben H. Winters's Android Karenina (Quirk Books, 2010), a "mash-up novel," here. An interview with Winters, here.
&, of course, Jane Slayre, by Charlotte Bronte and Sharri Browning Erwin (Gallery/Simon and Schuster, 2010) here; Little Vampire Women by Louisa May Alcott and Lynn Messina (HarperTeen, 2010) here; and Pride and Prejudice and Zombies, Sense and Sensibility and Sea Monsters, Wuthering Bites, and many, many more.