Each of the first three pieces of DLC is just a skin, just a texture and model. Just, ya know, Horse Armor. Those in Europe will receive a download code for their Dress-Up Ninja™ DLC packs as their pre-order bonus, but the rest of us will have to pay 200pts per pack if we want them. And sadly, (so long as there is some sort of Hurricane-Pack-thing as well) we really do want them.
Update: Microsoft has clarified that the 200 point DLC will in fact contain five new costumes, not just one.
[Thanks to everyone who sent this in!]