Rideable, mountable, pilotable dragons are coming to Skyrim, according to filenames lifted from the game's most recent update. The data hints at an upcoming DLC pack, possibly titled 'Dragonborn', that will add mounted dragon combat as well as new locations from as far afield as Elder Scrolls III's Morrowind.
As well as saddleable dragons, a series of uncovered quest markers point at the following locations: