@epr.eth
always comes from the self-publishers and independent authors/publishers first. they're more likely to experiment. for example; 50 Shades of Gray was originally published as Edward and Bella Twilight fan fiction. A PDF was being passed around (if i rememeber correctly) and ereaders were quite popular with the indy crowd. not sure what will pop off first, but whatever it will be it will be a book, story, or author plucked from these experimental forms and brought into the trad publishing world.