As head of the Justice Department's criminal justice division, Breuer took much heat from Republicans for the "Fast and Furious" gunwalking operation.
The agency's new executive has 30 years experience with similar roles in the public and private sector, most recently at the Treasury Department.
The Mexican-American labor secretary may make a run for office. Sources say she is eyeing the role of L.A. County supervisor.
Multiple news outlets have reported that Tim Geithner will leave his post by the end of January, regardless of whether Congress and the White House have forged a deal to raise the debt ceiling.
The Washington Post's Capital Weather Gang reports that Jane Lubchenco, the head of NOAA, is leaving the agency at the end of February.
The Pentagon's top lawyer, who deal with a host of controversial issues during the president's first term, will step down at the end of the year.