A long time ago, I prophesied that The Voyage of the Dawn Treader was going to be a pig to adapt to the screen, because of the episodic nature of the plot and the lack of a strong narrative.
http://lil-shepherd.livejournal.com/82563.html#cutid1 I have yet to see the movie, but listening to Mark Kermode reviewing it yesterday I felt a creeping smugness. Mark's description suggested that they have had to add a 'collect the tokens' plot to give the structure a spine. Also, he complained about the movie's episodic nature and lack of narrative drive.
I shall be interested to see how they've tackled the problems, and how well they've actually succeeded.