I borrowed a copy of Pride and Prejudice and Zombies, by Jane Austen and Seth Grahame-Smith, from Claire, and read it in the two days before she heads back to Canada. Here are a couple of quick thoughts:
It's about as true to the original Pride and Prejudice as the Bollywood production Bride and Prejudice, and should be taken in approximately the same spirit. That is, you don't read it because it's a classic. Really, it's just rather pulpy summer fiction, dressed in regency garments and fighting ninjas.
I almost didn't finish it because of a couple instances of very graphic violence. I'm actually better able to accept violence in a movie than in a book, because a movie doesn't involve me as personally or actively in creating the image. A movie does all the work for me of picturing the carnage; but a book requires me to create the image myself. As Emerson Cod once said, "When you say 'monkey in a bellhop suit driving a delivery truck, I have to SEE a monkey in a bellhop suit driving a delivery truck."
It's most entertaining to see how Seth Grahame-Smith is able to insert small tweaks that change the meaning of the whole dialogue: the best example is during Elizabeth's visit to Lady Catherine, when she is talking to Colonel Fitzwilliam and Mr. Darcy. In the original, she is playign the piano, and says something like "my fingers await your command." In the Zombies edition, she is practicing handstands on her fingertips, but the original dialogue remains exactly the same.
Overall, an entertaining read, but I probably won't bother buying it. See if your local library has a copy.