When Skyrim's "Dawnguard" DLC was first outed by a trademark filing back in March, we knew little aside from the name – references to the Dawnguard could be found in Skyrim, but only vague ones. It wasn't even clear that the filing was for DLC at the time – nor is it clear today that a recently unearthed trademark filing by Bethesda parent company Zenimax Media for "Hearthfire" is Skyrim's next DLC.
But it sure smells like it. The term "Hearthfire" (or "Heartfire") correlates to the ninth month in The Elder Scrolls' world of Tamriel, as well as a set of books in the 2920 series. Bethesda is staying mum for now, telling VentureBeat that the studio, "does not comment on trademark filings." The filing was made back in May, so it's always possible that the idea has since passed.
The filing is definitely game software, per the description: "Computer game software for use with computers and video game consoles; downloadable computer game software offered via the internet and wireless devices." There's also a wholly unremarkable image alongside the trademark filing, seen above.