Ok, that is kind of interesting. According to wikipedia and amazon this book came out a year ago, it is/was originally by Ariane Sherine (of the atheist bus advert campaign).

hardcover = http://www.amazon.com/Atheists-Guide-Christmas-Ar... (the Kindle version is the same)

but paperback = http://www.amazon.com/Atheists-Guide-Christmas-Ro...

Is it just a new version? It doesn't look like it from the description and reviews.