Baker confirmed that she is leaving the post on June 3, but did not say what her intentions are. Comcast/NBC, however, issued a release saying she will join Comcast as senior vice president of government affairs, NBCUniversal.

“I am privileged to have had the opportunity to serve the country at a time of critical transformation in the telecommunications industry,” she said in a release. “The continued deployment of our broadband infrastructures will meaningfully impact the lives of all Americans. I am happy to have played a small part in this success.”

Baker said the focus on spectrum reform was the most important issue she confronted at the FCC.

“I depart most proud of our collective efforts to focus on long-term comprehensive spectrum reform,” she said. “It is the most important step we can take to ensure our nation’s competitiveness in an increasingly interconnected world.”

Kyle McSlarrow, president of Comcast/NBCUniversal for Washington, said the company was pleased to have her.

“Commissioner Baker is one of the nation’s leading authorities on communications policy and we’re thrilled she’s agreed to head the government relations operations for NBCUniversal,” McSlarrow said in a release. “Meredith’s executive branch and business experience along with her exceptional relationships in Washington bring Comcast and NBCUniversal the perfect combination of skills.”

While Baker is barred from lobbying the commission for two years, her decision to leave the commission so soon after it approved the merger of Comcast with NBCUniversal raised some eyebrows.

“As recently as March, Commissioner Baker gave a speech lamenting that review of the Comcast-NBC deal ‘took too long.’ What we didn’t know then was that she was in such a rush to start picking out the drapes in her new corner office,” Free Press President and CEO Craig Aaron said in a release.

The move is another example of how the problems caused by too-cozy relationships between the regulators and the regulated, Aaron explained.

“Sometimes the revolving door between government and private industry spins quickly and sometimes it’s on a rocket sled,” Dave Levinthal, communication’s director for the Center for Responsive Politics, told POLITICO. “This transition is as quick as it can possibly get.”

While Baker is not allowed to be an official lobbyist, Levinthal noted that she has many ways to be influential and lobby for her new company in a broader sense.

“It’s a big boon for Comcast,” he said. “They are getting somebody who has unbelievable government experience and know-how” in the communications space. Consumers, he noted, can’t afford to hire someone of a similar stature to advocate for them.

In a recent speech she made about reforming the FCC’s merger review process, Baker said she failed to see the “nexus” of connection between the commitments Comcast made to deploy additional broadband facilities and to design a low-income program and the transaction. However, she did note support for the initiatives as a positive development in and of themselves.

But Baker’s ability to influence the commission and administration officials on the issue is limited. By federal law, former employees are barred from “knowingly, with the intent to influence” contacting government employees on an issue in which they “participated personally and substantially as an employee.”

Despite some carping, Baker got generally high marks for her service at the commission.

“With a winning combination of integrity, intellect and experience, Meredith Baker will be a key player for NBCUniversal, and I know that her in-depth knowledge of broadcast issues, deep understanding of the D.C. landscape and strong leadership abilities will make her an important resource for the entire broadcast industry,” said National Association of Broadcasters President and CEO Gordon Smith.

Baker’s decision caught many the telecom world flat-footed and the question of her successor was up in the air.

Sources told POLITICO that one logical choice is the Senate Commerce Committee’s Republican chief counsel Brian Hendricks. Sen. Kay Bailey Hutchison (R-Texas), the ranking member, is retiring when her term expires.

Other names mentioned include Neil Fried, senior GOP House Energy and Commerce Committee counsel, and Matthew Hussey, a senior aide to Sen. Olympia Snowe (R-Maine).

Baker was nominated by President Barack Obama as a member of the FCC on June 25, 2009, and was sworn in on July 31, 2009.

She previously served as acting assistant secretary of Commerce for communications and information and acting administrator of the National Telecommunications and Information Administration. The NTIA is the president’s principal adviser on telecommunications and information policy.

Baker was named deputy assistant secretary in February 2007. She first joined NTIA as a senior adviser in January 2004.

Baker, a Texan, is a member of a well-known Republican political family as she is married to the son of former President Ronald Reagan’s chief of staff James Baker.

Her decision could give Obama two more appointments to make to the commission. Commissioner Michael Copps’s term expired in 2010, but he can serve until the end of this congressional session.

Baker’s term ends this year, but she could have served until the end of the next session of Congress. That could create political problems as appointments are seldom made in an election year. The commission, by law, must have two members who are not of the same party as the sitting president. The FCC is currently made up of three Democrats and two Republicans.

Jessica Rosenworcel, the Senate Commerce Committee’s senior communications counsel, is the most often mentioned name to fill Copps’s slot on the commission.

CORRECTION: In earlier versions of this article, Baker’s family connections were misidentified. She is married to the son of James Baker, the former White House chief of staff.

This article first appeared on POLITICO Pro at 2:45 p.m. on May 11, 2011.