Department of State: Secretary John Kerry

(Saul Loeb/AFP/Getty Images)

Status: confirmed

Biggest tasks: Most pressing for the new Secretary of State is negotiating with Iran and North Korea, and navigating the U.S.'s role in the escalating crisis in Syria.

Environmentalists are also hopeful that Kerry, a climate change advocate, might slow what seems like the current fast-track to presidential approval of the Keystone XL pipeline.

So far, Kerry has freed $250 million in aid to Egypt, agreed to provide $60 million in nonlethal assistance to the Syrian opposition, and cleared once and for all that basketball player Dennis Rodman is not a U.S. diplomat.

Background: Kerry's nomination was pretty uncontroversial in the Senate: Only three senators voted against him. He sailed to nomination after Republican senators struck down Obama's first pick: U.N. ambassador Susan Rice. Kerry is a military veteran, former head of the Senate Committee on Foreign Relations, andeven the child of a U.S. foreign service officer. Check out the New York Times magazine's 2011 profile that shadows Kerry's trip to Afghanistan and Pakistan.

Department of the Treasury: Secretary Jacob (Jack) Lew

(Mandel Ngan/AFP/Getty Images)

Status: confirmed

Biggest task: According to the Wall Street Journal, overhauling the corporate and individual tax codes are at the top of his to-do list. He'll be in the middle of the ongoing budget battle, advising on how to cut the cost of entitlement programs. International economic issues, like setting a market-based exchange rate with China, are also a priority.

Background: Lew has faced questions about his high-ranking positions at Citigroup, where he worked just before the bank was bailed out with $45 billion in taxpayer money. He was also under scrutiny for his unusually high compensation at New York University. He earned more than almost every university president(including NYU's) for his post as a VP of Operations, and received a $685,000 bonus when he left the post for Citigroup.

Department of Defense: Secretary Chuck Hagel

(Saul Loeb/AFP/Getty Images)

Status: confirmed

Biggest task: Hagel's immediate job will be navigating the $46 billion in sequester cuts to the Department of Defense, roughly nine percent of the Pentagon's budget. He'll also oversee the U.S. drawdown of the war in Afghanistan.

Background: On the right, senators led by Lindsey Graham said Hagel wasn't supportive enough of Israel, pointing to his previous use of the term "Jewish lobby"(which he later disavowed). Conservatives also feared he wouldn't be willing to take a hard stand against Iran or North Korea, after voting against unilateral sanctions in the past.

Every Democratic senator voted for Hagel's confirmation, despite his staunchly conservative record on issues like the Iraq War and the Patriot Act. He drew some ire from LGBT activists on both sides of the aisle for questioning in 1998 whether an "openly, aggressively gay" nominee should serve as a U.S. ambassador (Hagellater apologized for the remark).

Central Intelligence Agency: John Brennan

(Alex Wong/Getty Images)

Status: confirmed

Biggest task: Brennan will take over the CIA's drone program and must navigate a potential fight over a classified Senate study that is critical of the the agency's use of torture during the Bush years.

Background: A 25-year CIA veteran, Brennan held positions at the agency including station chief in Riyadh, Saudi Arabia, in the 1990s. After he advised Obama on intelligence during the 2008 campaign, his potential candidacy to lead the CIA drew intense opposition from human rights groups because of Brennan's role at the agency during the Bush administration. He withdrew his name from consideration the CIA job and Obama instead named Brennan the top counterterrorism adviser in the White House.

Brennan's nomination drew a 12-hour talking filibuster from Sen. Rand Paul, R-Ky., who demanded the administration answer whether drones could be used against U.S. citizens on American soil. Paul ultimately elicited a qualified "no" from the administration and Brennan was confirmed on a 63-34 vote.

During his confirmation hearing before the Senate Intelligence Committee, Brennan made two promises that are likely to come up during his tenure at the CIA. Asked about what the U.S. should do when drones killing civilians, Brennan said, "We need to acknowledge it publicly." He seemed to qualify that statement, adding that such acknowledgements would be "the ideal" and "the objective of the program." The U.S. has not previously acknowledged civilian deaths from specific drone strikes.

Brennan also pledged that he would take "under serious consideration" a request to declassify the Senate's report on CIA interrogation and detention. The agency recently missed a Feb. 15 deadline to respond to the Senate's report.

Department of the Interior: Sally Jewell

(Cliff Owen/AP Photo)

Status: nominated

Biggest task: Jewell would oversee both conservation efforts and the development of federal land for energy production.

Background: Jewell's a D.C. outsider, never having served in government. Previously, she was the chief executive of the outdoor equipment company R.E.I.

Republican senators have said they're wary of her environmental advocacy, specifically her position as a board member for the National Parks Conservation Association. Jewell has said she supports Obama's "all of the above" approach to energy production.

Department of Energy: Ernest Moniz

(Mandel Ngan/AFP/Getty Images)

Status: nominated

Biggest task: Moniz enters office at a time of escalating debate on the safety and environmental impact of fracking. It will also be his job to oversee Obama's "all of the above" energy policy, which includes renewable energy and increasing oil production.

Background: Moniz worked as a nuclear physicist and director of the Energy Initiative at the Massachusetts Institute of Technology. Environmental groups saythe program received considerable funding from oil and gas companies. They're also unhappy with his support for fracking.

Chief of Staff: Denis McDonough

(Jewel Samad/AFP/Getty Images)

Status: appointed

Biggest task: McDonough is Obama's actual right-hand man and adviser on both foreign and domestic policy issues.

Background: McDonough's been close with the president after serving as a foreign policy adviser on the 2008 campaign. Since then, he's been a deputy national security adviser. McDonough has been described as one of Obama's "most loyal and trusted confidants," with access to and influence on the president far surpassing his position. Washington Post and the New York Times have profiled the somewhat mysterious deputy adviser.

Office of Management and Budget: Sylvia Mathews Burwell

(Win McNamee/Getty Images)

Status: nominated

Biggest task: The head of the OMB will help Obama draft his next budget proposal to Congress — a particularly heavy load amid ongoing congressional budget battles. The office will also oversee government agency performance, as they try to mitigate the impact of sequester cuts.

Background: Burwell's most recent role was as head of the Walmart Foundation. Though Burwell worked for the philanthropic arm of the corporation, The Nation has reported the Foundation may give to organizations in an attempt to further Walmart's political interests. For example, the Walmart Foundation gave a $200,000 grant to the national NAACP, while the New York NAACP chapter endorsed opening a New York City Walmart store.

Before moving to philanthropy through the Walmart Foundation and the Bill and Melinda Gates Foundation, Burwell had a long list of economic policy positions in the Clinton administration. She served as the staff director of the National Economic Council as well as deputy director of the OMB under now Treasury Secretary Jack Lew.

Environmental Protection Agency: Gina McCarthy

(Alex Brandon/AP Photo)

Status: nominated

Biggest task: McCarthy has a big job ahead, heading the EPA as it decides regulations on carbon emissions from power plants, fracking and other air pollution issues.

Background: As the current head of the EPA's Office of Air and Radiation, McCarthy had a big hand in passing landmark auto emission standards. She also led an effort to create a regional cap and trade program. Both have conservatives saying she'll prioritize environmental regulations at the expense of job creation and energy independence. But like all of Obama's nominees, McCarthy has stated support for his approach to energy policy, which includes increasing domestic gas production.

Department of Labor: Thomas Perez

(Sean Gardner/Getty Images)

Status: potential nominee

Biggest task: Perez would play a main role in two of Obama's major policy proposals: raising the federal minimum wage and overhauling our immigration system.

Background: Perez currently serves as the assistant attorney general for the civil rights division in the Justice Department. He has been a champion of several civil rights issues, from voter access to fair housing, garnering him the support of groups like the NAACP. Washington Post reports that under Perez, the DOJ's civil rights division also conducted more investigations of police and sheriffs departments than any year in the division's history.

Perez's confirmation could be a controversial one, with Sen. Chuck Grassley and other conservatives calling for more information about his role in a 2012 fair housing case.

Department of Commerce: Penny Pritzker

(Charles Dharapak/AP Photo)

Status: potential nominee

Biggest task: The Commerce Department include a surprising a bit of a hodgepodge of US agencies, from the Bureau of the Census to the National Oceanic and Atmospheric Administration. There's been multiple proposals to abolish it —some more legitimate than others. The head of the Department also oversees all things trade.

Background: Hyatt Hotel heiress Pritzker served as Obama's chief fundraiser in his first election. In response to nomination rumors in 2008, Pritzker stated she would not put herself up for consideration.

Though she cited family obligations, many suspected a series of family financial scandals would make her confirmation difficult in the midst of an economic crisis. The Pritzker family, worth an estimated $15 billion, has been sued by the IRS for their holdings in overseas tax shelters. Some have also cast skepticism on theirownership of Superior Bank, a mortgage bank that Pritzker helped run, which issued the kind of subprime loans fueling the foreclosure crisis. In 2001, the Pritzker family settled a $460 million FDIC lawsuit over Superior's collapse.

Pritzker and her family have also been main targets of organized labor. The Hyatt chain is fighting a "Hyatt Hurts" boycott campaign that deems them "the worst hotel employer in America." Pritzker has also been a vocal advocate and funder of the charter school movement, leading the Chicago Teachers Union to protest Pritzker outside the Hyatt on Chicago's Michigan Avenue.

Secretary of the Departments of Labor and Transportation are also newly vacated. Multiple rumors remain about who Obama will nominate for both positions. Ed Montgomery has been said to be among top picks for labor secretary. For transportation, many have pointed to Deborah Hersman as a potential nominee.