The next Elder Scrolls V: Skyrim DLC will be called Dragonborn and will feature dragon mounts in some capacity. At least that's the word according to a post on the Bethesda forums which claims to have uncovered the information after digging through the source code of the most recently released Elder Scrolls V: Skyrim patch.
Other key points of interest extracted from the code:
- The DLC will take place on the island of Solstheim
- Main locations will be Raven Rock, Miraak Temple, Castle Karstaag, and Telvanni Tower.
- New Bonemold, Chitin, Nordic, and Stalhrim armour types
- New creatures (not specified)
- New Dwemer Artifacts (not specified)
- PS3 Downloadable Content is mentioned (nothing specific)
Obviously all this info is currently 100% unconfirmed by Bethesda, but it’s worth remembering clues to Skyrim’s Dawnguard DLC were similarly discovered in an update patch pre-release which turned out to be accurate.