In May, ZeniMax filed a trademark for the term "Hearthfire," which is equivalent to the month September on the Tamrielic calendar. Although the
company claimed ownership over this term a couple of months ago, it is likely that the rumor mill is churning again since September is almost here.
Perhaps a new "Skyrim" DLC will be unveiled next month? ZeniMax
claimed ownership over the term "Dawnguard" in April, roughly about two to three months before the DLC was released last June. The trademark for "Hearthfire" was filed in late May, and if Bethesda announces new DLC content next month, it will be a similar time frame.