I am (embarrassed to say) just now reading the Da Vinci Code and am absolutely absorbed in it. I'm quite sure my family wants me to "shut up about it already"!
"Jesus Loves Me This I Know"... but dang... the whole theory/conspiracy/controversy sounds plausible to me. Cheers to Dan Brown for putting this obviously timeless mystery into a novel that enlightens, intrigues and entertains all at the same time.
I surely don't see Tom Hanks as Langdon, but his ability to capture while playing worthy characters is proven and I'm sure will be equal to the challenge to satisfy the imagination.
As stated by GravityRobert, above, very few books make the transition from book to film as they were written or intended. If bad screen plays, editing, or rewriting doesn't screw them up and disappoint, then bad casting does!
Listing one, I have to say that Larry McMurtry does seem to have been lucky in this regard....and I thank God for Suzanne De Passe and "Lonesome Dove". (Robert Duvall, Tommy Lee Jones, Danny Glover, Angelica Huston, Robert Urich & Rick Schroder)
Here's to hoping they make as great a movie out of The Da Vinci Code as has been the book!