Update: Some more rooting around in the 1.8 patch code has led to a fresh discovery: spears. Several references to spear attack animations were found, which is encouraging news for players felt like their weapons were just too short. Hopefully their are some more Dragonborn surprised remaining in the Skyrim patch code.
The nerds have completed their inspection of every line of code in The Elder Scrolls V: Skyrim's latest patch, and hints at upcoming DLC have been found! Touchdown! Fragments of data were found referencing a number of potential addition, but as always these details are simply rumors. It's impossible to tell if any of this is something Bethesda will be releasing, if its meant to be a red herring, or if it's meant for a different DLC pack down the line. Nevertheless, here's what we know about 'Dragonborn'.
Dragonborn, as its referenced in the code, takes place on the island of Solstheim -- east of Skyrim and northwest of Vvardenfell, but not belonging to any territory in particular. One can only assume there will be dragons on Solstheim, because Dragonborn will apparently give the ability to ride said dragons.
A myriad of contextual references are also made throughout the code: Locations -- Raven Rock, Miraak Temple, Castle Karstaag, Telvanni Tower; Armor Types (possible horse armor) -- Bonemold, Chitin, Nordic, Stalhrim; Enemy Types -- Riekling, Scrib, Netch, Benthic Lurker. Suffice to say, Dragonborn looks to be a Dawnguard sized package.
Hopefully Bethesda will take control of the situation before rumors start to become too rampant and we'll hear a Dragonborn announcement for Skyrim soon.