In something of a surprise move, the White House announced earlier today that Department of Labor Secretary Hilda Solis is resigning from her post:

In a statement, President Obama thanked the former Southern California congresswoman for her long career in public service, calling her a “tireless champion for working families.”

“Over the last four years, Secretary Solis has been a critical member of my economic team as we have worked to recover from the worst economic downturn since the Great Depression and strengthen the economy for the middle class,” Obama said. “Her efforts have helped train workers for the jobs of the future, protect workers’ health and safety and put millions of Americans back to work.” …

Solis was one of five female Cabinet secretaries, and one of two Latinos, along with Interior Secretary Ken Salazar. Three other women hold Cabinet-level positions, including the departing EPA administrator, Lisa Jackson.

No word yet on anyone being definitely considered to fill the position, but the White House may need to tread carefully on that one amid criticisms recently swirling around the Obama administration’s range of senior-level diversity:

Obama will be under pressure to replace Solis and other members of cabinet who are leaving with female candidates, following complaints that his selections so far have shown insufficient diversity.

Carney insisted however on Wednesday that women were key players at the top of the president’s inner circle, after a front page photo in the New York Times ruffled the White House by showing Obama surrounded by male advisors.

“Women are well represented in the president’s senior staff here. Two of the three deputies, deputy chiefs of staff, are women. The White House counsel is a woman. A woman runs Homeland Security for this country, Secretary (Janet) Napolitano.”

On that note, the White House did confirm that a few of Obama’s lieutenants will be sticking around for at least awhile yet, although LaHood’s fate is still up in the air:

Transportation Secretary Ray LaHood is not among a group of Cabinet officials the White House said Wednesday was staying on the job in President Obama’s second term.

The White House has confirmed that Attorney General Eric Holder, Health and Human Services Secretary Kathleen Sebelius and Veterans Affairs Secretary Eric Shinseki will continue to serve in their respective posts.

Missing from the list is LaHood, who said previously that he was retiring after Obama’s first term, but has appeared in recent weeks to backtrack.

President Obama’s picks to head up his second-term national security team are in for what will surely be a testy confirmation battle, but I’m still eagerly wondering who he will select for his second-term energy-and-environment team. We’re waiting on whether Interior Secretary Salazar will ‘decide’ to stay or to go, but EPA Administrator Lisa Jackson is definitely on the way out and Energy Secretary Steven Chu very probably is; who President Obama picks as their replacements will likely be a pretty good indicator of the direction in which he intends to take his energy policy over the next few years, which will have heavy repercussions for our economy in general:

“When the Obama team came in the first go around, there was great hope that the president would be transformative and really try to shift the energy policy much more heavily towards renewables,” Charles Ebinger, an energy policy expert at the Brookings Institution in Washington, said in an interview.

Instead, the growth of hydraulic fracturing to drill for oil and gas in shale rock formations is offering a “unique opportunity to revitalize the American economy and reinvigorate American manufacturing,” Ebinger said. …

“The whole paradigm has shifted over the last four years,” Stephen Brown, a lobbyist for Tesoro Corp. (TSO), which is based in San Antonio, Texas, said in an interview. The administration needs to “figure out how not to get in the way of this,” he said. …

“He needs a couple of people at the top who can go out and sell the message that we really are at a situation now where we can reduce our oil import dependency if we move to develop these unconventional resources,” he said. “I think he needs a salesman or a saleswoman.”