The only difference is that this was a book...a well written book at that (I think even on the N.Y. Times Best Seller list for a while). It will already have a built in audience from book readers who are interested and if they try to at least keep it as close to the book as possible; it should do well at the box office. A lot of 150 year Civil War Anniversaries this year plus a blockbuster Lincoln movie being released in 2013? by Spielberg.
"The farther we go, the more the ultimate explanation recedes from us, and all we have left is faith."
~Vaclav Hlavaty