It looks like Bethesda has something up their sleeves, as a post on Twitter reveals a new image teasing a full trailer for Monday. The image looks to be for new Skyrim DLC, as the character in it is wearing something similar to a Dragon Priest Mask and Robes crossed with Falmer gear (at least in shape).
Odds are good this reveal is for the rumored Dragonborn DLC that was mentioned in some lines of code for the 1.8 patch for The Elder Scrolls V: Skyrim. That DLC, if the rumor is true, returns players to the island of Solstheim off the coast of Vvardenfell, which we journeyed to in the Bloodmoon expansion for The Elder Scrolls III: Morrowind. The most interesting part of the rumor is the ability to ride dragons, so maybe that Dragon Priest/Falmer armor ties it all together.
Either way, be sure to check back here on Monday for the full trailer of whatever Bethesda is teasing.