Little tidbit of news. Apparently Bethesda has trademarked something, some group etc called 'Dawnguard'.
http://www.push-start.co.uk/all/announcements/dlc/skyrim-dawnguard-dlc-a-possibility/
Just a stab in the dark, but the name might hint at it involving Azura since she is the Goddess of Dusk and Dawn. Probably just wishful thinking but it would make sense. I mean, we know Sheogorath stole the Dark Seducers from Azura. If they were her Dusk soldiers then perhaps these Dawnguard are her Dawn soldiers.
Who wouldn't like a demonic army of Valkyries?

I mean, who better than Wonder Woman to voice act a demonic goddess?
Any other ideas on what it could be about?