Stephanie Meyer is an observant Mormon, and one thing that sets her vampire fiction apart (aside from huge sales numbers) is that there is no sex. There is lust, yes, there is heavy breathing, but there is no actual sex. Interestingly, Orson Scott Card wrote her bio for the Time list. He compares her to Jane Austen. I'm not sure I buy that comparison, but that might be because he's messing with my literary pantheon. But also, Austen's heroines, eve the quite young ones like Emma, were plainly women—old enough to marry, and by the end of the story, ready to marry. Meyer's heroine in this series is plainly an adolescent—more Dawson's Creek than Pride and Prejudice.
Her next series, however, is out and out science fiction—alien parasites invade the earth. The heroine is a grown-up woman with a job. It will be interesting to see if Meyer can draw the same level of audience with an adult story.
In other words, will she be on Time's list next year?