» Sat Jun 16, 2012 2:25 am
Dragonborn was registered sometime after Dawnguard and sometime before Hearthfire.
Whether it is DLC, we don't know, and we can't even be 100% certain about Hearthfire yet. That said, as Dragonborn is a central term in Skyrim, it is possible that they would seek to protect that term even if it isn't DLC, whereas Hearthfire is a tangential term in Skyrim, so its protection probably signifies they are doing something important with it.