Did they create anything new for the film? Well, yes and no. They did create some new pieces for the film, but the filmmakers did use swords and armor that were created for Prince Caspian and The Lion, the Witch and the Wardrobe, obviously. Their newsletter just went out that confirmed their limited involvement with The Voyage of the Dawn Treader, though, so I feel comfortable confirming that the rumor is true.
Weta also has a sale on some of their Narnia statues from The Lion, the Witch and the Wardrobe.