Seriously, this is kinda like the reaction to the "Satanic Verses" without the fatwa. Christianity is hardly threatened by this book.
That's the funny part. People think they are being bold by attacking Christianity. Let's see these people really be bold and attack Islam... I don't know if you've heard about this, but there is an "othercott" of the Da Vinci Code in the works.
http://othercott.com/
Not Christianity, but Catholicism is.