Bethesda have trademarked the name "Hearth Fire". Is this the first clue as to the second Skyrim DLC? If anyone has a view on this (and lets face it you probably do), then get discussing in the comments section, as I'd like to know what the general consensus on this is.
EDIT: The trademark is for downloadable software so DLC is likely and 2920, vol 09 - Hearth Fire is the name of a skill book from the past 3 TES games. Not sure how much that is to do with anything, just interesting to note.
Info from various pages (and more can be found if you want to search for it):