When I was seeing Narnia: Prince Caspian tonight, for the second time in 3 days (haha), I heard a familiar voice speaking in a scene! So I checked imdb and I was right!

Predrag Bjelac, who played Igor Karkaroff in Goblet of Fire, was Lord Donnon in the movie. He only had a few lines, but still woo anyways!

Also as you probably know, Warwick Davis (Flitwick and the choir director) is also in the film as Nikabrik the dwarf.