What's the deal with the Da Vinci Code?

Okay, I heard something about a "fact page" that says all such and such material is "accurate." What does that mean? That the movie/book are based on historical facts?

What's the deal? Is the movie presenting any information as fact if it can't be backed up? Why is it causing such a buzz? The reports I read on it just confuse me I guess because I haven't read the book.

What's the big deal? What if tommorrow the pope declared that Jesus had a wife. What would happen?