Jasper Rees investigates the increasing appeal of children's books for an adult readership in a piece titled 'We're all reading children's books' in the Daily Telegraph. I haven't found an online link to this piece yet. If someone does before me, please post it as a Comment.
Although rather pedestrian in tone, this is one of the better, more balanced and common-sensical pieces on the subject. It includes soundbites from various authors (Almond, Burgess, Stroud, Haddon) and from Susan Jenvey, editorial director at Faber&Faber.
"Perhaps it all comes down," Rees concludes towards the end of his piece, "to the fact that, in a culture where everything is up for grabs, publishing is simply learning to live by the rules established by other media and other art forms. Just as in theatre and film adults will consume fare aimed at a younger audience, so publishing seems to be a lone voice in the wilderness trying to stop children growing up too quickly."
For the 'Just as... so...' construction in that last sentence, read 'Whereas...' for a better understanding of the point Rees is making.