It remains anyone’s guess whether the cameras will ever start rolling on The Voyage of the Dawn Treader, but one thing we do know is that the people who made the previous Narnia films have been working on the next one in pre-production for some time now.
The new DVD for Prince Caspian — which came out in Great Britain this week and comes to North American stores December 2 — includes a featurette on the previsualization of these films that ends with a few very, very brief glimpses of the work that has been done so far on Dawn Treader.
The image above is concept art that, I’m guessing, depicts the scene where Lucy goes looking for the Magician’s book. The image below is concept art for, presumably, the Dawn Treader itself:
Finally, the featurette ends with two brief animatic shots of a dragon flying over the water, then bursting out of the water and lunging at the camera. I do not know whether these shots depict the same dragon, or whether they are part of the same scene, or what.