Now Playing: 12-27-12 Marketplace

The U.S will hit its $16 trillion debt ceiling -- we explore how this affects the fiscal cliff. Jeremy Hobson talks to Memphis mayor AC Wharton about what happens to his city if we do go over the cliff. The Environmental Protection Agency's Lisa Jackson has announced that she will be stepping down. SeaWorld is going public. Curbside buses have extended their routes for the holiday travel season, even through not-so-populated places. And with 18 states and the District of Columbia now permitting medical use of cannabis with a prescription, along with Washington and Colorado legalizing recreational marijuana, there's a rise in opportunity for "pot-trepreneurs."