Flipped conferences could keep more of the traditional model than unconferences do. You could ask educational influencers with something important to teach the conference audience to speak. But instead of doing their teaching and presenting at the conference itself, they can work out an assignment for the attendees to complete in advance – a slide share, video of a speech, or a collection of reading materials – and then spend the actual conference time discussing, or workshopping, the ideas from the assignment.
HT @jimtiffinjr