Considering the seven-figures Variety reports Fox 2000 has already poured into the rights to turn the work into a film (news you should recall from Weinberg's article here), it's no surprise they're now breaking out an Oscar nominated screenwriting gun to help differentiate their vampire world from the rising cacophony of films it will be joining in the next year or two. In a secondary seven-figure deal, Fox 2000 has entrusted scripting duties to The Aviator, The Last Samurai, Sweeney Todd, and Gladiator screenwriter John Logan, with the ultimate intention of handing directorial duties to Gladiator helmer Ridley Scott. Though considering the log-jam of films Scott has in his 'maybe pile' at this point, I wouldn't hold your breath for that last part to see fruition.
However, it is safe to say that The Passage, which is the start of a hypothetical literary trilogy, will see the light of the silver screen some day. Ballantine has already paid $3.75 million for book publishing rights for Cronin/Ainsley to finish his story about a world in which the scientific exploitation of disease-curing South American bats causes the birth of an epidemic strain of vampirism. By my conservative tally, that means between the two corporations there's already at least $5-6 million invested in what sounds like little more than a variation on the film version of I Am Legend.
Either Fox 2000 and Ballantine have found a truly fantastic source for vampire tinted dollar signs, or a few (ir)responsible executives at both companies are currently busy sacrificing first borns to the Twilight Money Gods in the hope that they aren't too late to this trend. I'm all for a big scale Hollywood production involving vampires, particularly if it's going to involve Logan and Scott, but sinking that much coin into an unpublished, untested (and, frankly, not all that unique sounding) book franchise seems reckless.
If you're only looking to have some vampires of your own, Fox, just go pick up any of the countless blood sucking properties already in the public's conscious. I mean, The Little Vampire has to grow up one day, right?