For me, this is very exciting. St. Martin's Press defines it as: "great, new, cutting edge fiction with protagonists who are slightly older than YA and can appeal to an adult audience. Since twenty-somethings are devouring YA, St. Martin’s Press is seeking fiction similar to YA that can be published and marketed as adult—a sort of an “older YA” or “new adult."
That is how I would classify my own writing. I am thrilled that there may be a definite category for it soon. After all, we've all read about authors trying to get a book published with a 20-something protagonist, and being shot down because the book isn't "YA" but also isn't adult. So either the author dumbs down the character, or writes the age up to appeal to a genre. I agree that there should be and is an audience for characters in between ages.
How many of you would write new adult? How many of you would read it?