Sorry to evilly resurrect this thread.
I think some folks, though, are overestimating the inevitability of a NYT bestseller, even a worldwide one, turning into a major film franchise. Hollywood turns bestselling novels into films all the time. Da Vinci Code was one of the bestselling single titles ever appearing and remaining on or near the top long after hot selling Twilight titles came and went. The Time Traveller's Wife is another steady seller. That children's fantasy novel, "Unfortunate Events" or whatever it's called, is another very popular fantasy series that all kids under a certain age know about. None of these turned into a major worldwide phenomenon like Twilight when made into film.
Usually it takes properties with long term cred like Lord of the Rings to guarantee this kind of rabid support. Harry Potter, as a recent creation, is the only comparable series and, frankly, it was a property with a visibility way beyond that of Twilight before news of the inevitable film adaptations were released. You didn't need to do research, your bookstore was having midnight selling parties and your grandma was concerned about all the witchcraft. Harry Potter actors didn't need to do Comic Con. Summit pimped their Rob & Kristen so assiduously the first time out because they needed to encourage the hype and get the word out to realize the potential of a new franchise that filled a slot none of the others did, except maybe Hannah Montana (but still with a different appeal).