According to a patent filing today, Skyrim publisher Zenimax Media may already be planning the next downloadable content patch for the Elder Scrolls V: Skyrim.
Fusible reports that the filing showed up in the US Patent and Trademark Office database today, and was filed on May 24, 2012. The "Hearth Fire" name may reference the name of a mage skillbook within Skyrim, and speculation is that this could be a DLC that focuses on the mage class. Specifically, the Hearth Fire skillbook teaches Conjuration skills.
As interesting as this filing is (we were big fans of shooting flames and summoning demons as a Skyrim mage) it seems unlikely we'll be hearing much official information about this any time soon. E3 is next week, but with Dawnguard set to debut it's unlikely Bethesda will divert attention to another DLC.