evilneko said:
Point me to where it says that.
No reason to assume there's any more to it at this time. Two words: Horse Armor.
Lets look at the Dawnguard description shall we?
"Dawnguard? is the first official game add-on for The Elder Scrolls V: Skyrim® - the 2011 Game of the Year. The Vampire Lord Harkon has returned to power. By using the Elder Scrolls, he seeks to do the unthinkable - to end the sun itself. Will you join the ancient order of the Dawnguard and stop him? Or will you become a Vampire Lord yourself? Featuring an all new faction questline and locations, the ultimate choice will be yours."
No mention of all the new shouts, weapons, armor, the useable boats, the Flamer, the Dwemer stuff, the face changing, werewolf perk trees... you know... like 90% of the content. It only mentions the very core details of the DLC.
Also they did horse armor, once... and they have done like 10 DLC since then, and none of them have been like horse armor. If horse armor was something they did more then one time, you would have a point, but they haven't.