The Da Vinci Code

The film based on "The Da Vince Code" novel (which may or may not have be based in part on a non-fiction work) is due for release around the world soon. How much opposition to the film and its advertising will be mounted by the
Catholic Church - given the central premise of the book/film is that Jesus and Mary Magdalene had children and the blood line survives to this day. Already there have been calls for advertising on the side of an under-restoration state-owned church in Rome to be removed because it was a "provocation". And I think I read somewhere that Dan Brown, the author, in answer to possible concerns, pointed out that the was "just a novel" ie as in - it's just a story so what's all the fuss about?