Petition for Knight of the Order Cos ...
"Now, if there's huge public demand to make these available for purchase, we'd be silly not to revisit it, but right now things are exactly the way we originally intended - everyone gets at least one extra costume for the game."
quoted from the Steam Forums
So who hasn't had the chance to preorder the game and now would like to buy the Knight of the Order costume as a DLC afterwards? Talking about this one here: http://assets.robotentertainment.com/Orcs-Must-Die/Screenshots/costumes/Costume_KnightOfTheOrder.jpg