From Bloomberg:

Obama has let it be known from his holiday retreat in Hawaii, through unidentified advisers, that soon after New Years Day he plans to follow through on plans to expand the definition of who’s “in the business” of selling firearms—and who’s thus required to perform background checks.

There will probably be calls to challenge Obama’s authority to broaden the background check mandate without congressional involvement. Lawsuits and objections from pro-gun Republicans on Capitol Hill will likely follow, as has happened with other efforts by the administration to use executive authority in the environmental arena.