Oh, now I saw that. I also saw that information about why the player's dragon form has two legs and two wings, is given in a FAQs in the website. So, the dragon knight do not transform into wyverns, but really in dragons with two limbs and two wings.
(So, my cute avatar here is actually a wyvern's face?)
Another question: lots of talk is given about how dragon slayers have glowing eyes. Will we get that when we use a specific spell? Also, will we get that in dragon form, too?