Point of note:
I am dying to see this movie, and if you think the book is JUST a bible, then I think you're being foolish.
First: the directors are the Hughes Brothers. Prior works include Menace II Society, Dead Presidents, and From Hell. They don't seem like the type to beat people over the head with religion, but I suppose they could've found God in a big way some time recently. Doubt it seriously, but you never know.
Second: go to the website [http://thebookofeli.warnerbros.com/] and take a look at some of the background material. There are links to articles on post-apocolyptic survival, the American Stonehenge (which includes instructions for post-apocalyptic survival), and the development of carbon nanotube storage media which could store billions of bytes of data for EONS.
Does that sound religious to you???
Third: did I mention that the soundtrack and the visual style elements I've seen are all fucking amazing??? Well, that really doen't have anything to do with the religion angle, but still...
Will the movie involve philosphical and religious questions? Undoubtedly: as a previous poster mentioned, the apocalypse was supposedly caused by a religious conflict. I'm sure there will be some moral and ethical questions in there as well, because that's what the Hughes Brothers do best. But to say "Oh it's gonna be Christian propaganda" just because you saw a brief panning shot of a bible is ridiculously assumptive.
Seriously-- you people who see a bible (or any religious reference) and immediately write something off as being unacceptable/unintelligent/unworthy of your time are being just as narrow-minded and sanctimonious as the religious nuts.