The other day, a new trademark ZeniMax Media filed at the end of February was noticed by several sites. The trademark is for something called "Dawnguard," and it is for "computer game software for use with computers and video game consoles; downloadable computer game software offered via the Internet and wireless devices." Now, this does not mean Dawnguard is one of the two announced DLCs (so far) for The Elder Scrolls V: Skyrim, but it does have a certain ring to it. It could also be the second DLC since the name "Redguard" was trademarked by ZeniMax as well. Redguard is, of course, the name of a race of people in The Elder Scrolls universe, but also part of The Elder Scrolls Adventures: Redguard, a spin-off game set several centuries before The Elder Scrolls: Arena.
As for Dawnguard, it could center on the Mythic Dawn cult that was featured promiently in TES IV: Oblivion and received a side quest in Skyrim. Perhaps the Mythic Dawn make their return in the town of Dawnstar, but at this point everything is pure speculation until Bethesda and ZeniMax come clean. Who knows, Redguard and Dawnguard could both refer to that The Elder Scrolls MMO pegged to be revealed in May. Whatever the case may be, it looks like ZeniMax has something up its sleeve. If the two trademarked names are indeed DLCs for Skyrim, just remember both are 360-exclusive for a month.