I have just seen this on Dark Horizons website about Prince Caspian:
"Dean Wright, the Oscar-nominated visual-effects supervisor for "The Chronicles of Narnia: The Lion, the Witch and the Wardrobe", told SCI FI Wire that he and his colleagues are already looking ahead to the sequel, "Prince Caspian".
Wright also confirmed that the sequel will bring back the main animal character, Aslan (voiced in the first film by Liam Neeson), as well as a host of familiar and new creatures - "There's new hero creatures, specifically Badger and his mouse, Reepicheep. Again, there's huge battle sequences. I know from talking to Andrew just briefly before he left: He wants to make this bigger and better than The Lion, the Witch and the Wardrobe".
Director Andrew Adamson hasn't written the sequel's script yet, but Wright said the effects team will begin computer "pre-visualization" of scenes from Prince Caspian "probably in a couple of months, and then full on into preproduction. You know, the film is going to kick off before you know it, and we'll be going like gangbusters, probably, I would say, within the next two to four months".
"One of the challenges [is that] it's described in the text that he does increase in size. At one point, he's finally referenced as being the size of an elephant. That's where interpretations of the filmmakers are going to come into play, how to pull it off... [Also] ee successfully avoided Aslan getting doused in water in this. But as soon as we get into the Dawn Treader [a ship that figures in Caspian] and that sort of stuff, it's going to be harder to avoid" says Wright."