President Bush named Tony Snow to be his White House press secretary on Wednesday in the latest round of staff changes in the West Wing.

"I am here to break some news," Bush told the White House press corps in the briefing room. "I have asked Tony Snow to be my press secretary. Tony already knows most of you. He agreed to take the job anyway."

Snow, former host of FOX News Talk's "The Tony Snow Show" and anchor of "FOX News Sunday," will replace outgoing spokesman Scott McClellan. Snow had been considering the White House's offer for the last several days.

“I am very excited and I can’t wait,” Snow said. “I want to thank you, Mr. President, for the honor.

"One of the things I want to do is make it clear that one of the reasons I took the job is not only because I believe in the president, but because believe it or not, I want to work with you," Snow said. "These are times that are going to be very challenging, we’ve got a lot of big issues ahead and we’ve got a lot of important things that all of us are going to be covering together."

Bush also praised outgoing spokesman McClellan, saying he will always be proud to call him “friend.”

“I’ve known Scott since he worked for me in Texas. We traveled our state together, we traveled our country together and we have traveled the world together. We have also made history together,” Bush said. “Scott should be enormously proud of his service to our nation in an incredibly difficult job. I will always be grateful to him.”

The talk radio host was given a clean bill of health by his oncologist Tuesday, following a CAT scan and other tests that were undertaken last Thursday. Sources said Snow was Bush's first choice, but he needed the all-clear from his doctors before he took the job. Snow is recovering from colon cancer.

Snow is the latest new player to join Bush's team in an administration shake-up that began with former Chief of Staff Andy Card's resignation, later followed by McClellan stepping aside. Josh Bolten took over Card's position last week. Snow said he expects to begin a transition into his new job the week of May 8.

Sources say Snow demanded more access to the Oval Office, wanting more power to shape policy than past press secretaries.

“He’s not afraid to express his own opinions. Those of you who have read his columns or listened to his radio show, he sometimes has disagreed with me. I asked him about those comments, and he said, ‘You should have heard what I said about the other guy,’” Bush said.

Some critics point to Snow's criticisms of the president's policies in the past as a cause for possible discord in the White House, but Martin Frost, a former Texas Democratic representative, said Snow will just have to tamp down on those in his new position.

"I think Tony obviously has credibility ... He's somebody that the press respects. He'll obviously have to tone things down a little bit if he's criticized the president on some past issues. He's the president's spokesman now and he can't differ with the president," Frost said.

Snow is a good choice for the position because he has a good reputation, Frost said.

"I think he was a good choice and I think it's good for the president to put somebody out with somebody like Tony who has credibility and let's hope that people can work together in Washington a little bit more," Frost said.

Lanny Davis, former White House counsel to President Bill Clinton, said Snow should not be compared to more divisive radio talk show hosts like Rush Limbaugh and Laura Ingraham.

“I hope that the Republicans don’t try to label him as a right-winger because he’s a conservative, but he’s a man of fairness and integrity. I think he will have a great deal of credibility on behalf of President Bush,” Davis said.

Democrats were quick to blast Bush’s pick, saying Snow is not the fresh start the administration needed.

"This is an interdepartmental move from one part of the conservative infrastructure to another that allows a darling of the right-wing to deliver the same misleading message, cherry-picked information and spin to the American people," said Karen Finney, Democratic National Committee spokeswoman.

Snow will be able to employ his humor in the new position, said Barbara Comstock, a former director of research and planning at the Republican National Committee.

"He has a great common sense, a great understanding of the issue. He is able to do it with good humor. We see him handle cancer with good humor, I think he can handle (NBC's) David Gregory with that same great humor, but also be somebody who would really communicate to the American people in a good common sense way," Comstock said. Gregory is known to aggressively challenge McClellan during daily press briefings.

Snow told FOX News' Bill O'Reilly last week that he was considering the job, but realized that it would come with a lot of responsibility, time away from his family, a "massive cut" in pay and other demands.

"There's no guarantee after you get out of the White House whether there's any landing place," Snow told O'Reilly.

Snow joined FOX News in 1996, when he launched the Sunday morning talk show that airs across the network. He then moved to FOX News Talks, the radio network, to be a morning show host. He still anchors "Weekend Live with Tony Snow" and contributes as a FOX News political analyst.

Snow, a former speechwriter for President George H.W. Bush, has interviewed Bush administration figures, including Vice President Dick Cheney, Secretary of State Condoleezza Rice, former Secretary of State Colin Powell and Secretary of Defense Donald Rumsfeld. He has also interviewed congressional and world leaders.

In 1991, Snow took a sabbatical from his job as editorial page editor at The Washington Times to work in the White House for President George H.W. Bush. He first served as the deputy assistant to the president for communications and director of speechwriting, and later as deputy assistant to the president for media affairs.

Snow earned his bachelor’s degree in philosophy from Davidson College in Davidson, N.C. He grew up in Cincinnati and currently resides in Virginia with his wife, son and two daughters.

Fred Barnes, editor of The Weekly Standard and a FOX News contributor, said Snow would be a good fit with the White House press corps, will likely offer greater access to the president than McClellan did and that he will spend a lot of time with the president.

"He's a major media figure, he's someone people know all over the country," Barnes said. "I think what he'll bring is greater access to the president. ... I think reporters in the press room are going to see a press secretary who fights back very toughly."

"If I were to take a job like that, no, I wouldn’t come in there and try to beat them up. But on the other hand, you have to stand your ground, you have to know what the facts are and you’ve got to know your brief," Snow said.

Other prospective names to replace McClellan were former Pentagon spokeswoman Victoria Clark and Dan Senor, the former Coalition Provisional Authority spokesman in Iraq. Senor, now a contributor on FOX News, served the U.S. civil administrator in Iraq, Paul Bremer.

More changes could still be on the way in coming weeks, as Bolten shapes his team.

U.S. Trade Representative Rob Portman was nominated for Bolten's spot at the Office of Management and Budget, and more and bigger names could still come.

Bolten told staffers to let him know if they were planning on leaving the White House before the end of the year because he wanted to "re-energize the team." Shortly after that discussion and McClellan's resignation, the White House announced that longtime presidential adviser Karl Rove was also jumping ranks.

Just over a year ago, Rove was promoted to deputy chief of staff in charge of most White House policy coordination. That new portfolio came on top of his title as senior adviser and role of chief policy aide to Bush.

Rove is shifting from overseeing policy development to return to his forté as a political adviser, a switch that comes about eight months before the November midterm election. Rove's position as deputy chief of staff for policy goes to Joel Kaplan, current White House deputy budget director.

Saying he was "ready to move on" after more than two years as the president's mouthpiece, McClellan told reporters Tuesday that he didn't expect any announcements that day, but one could come none too soon for him.

“I’m doing my part to push it along,” McClellan joked to reporters, adding at a later briefing, “I’m still here for a little while.”

McClellan, who has served in the job since replacing Ari Fleischer in June 2003, plans to leave in about two weeks.

Last week, Bush said McClellan had performed a "job well done," and the two touched on their long relationship predating the presidency.

"I thought he handled his assignment with class, integrity," the president said. "It's going to be hard to replace Scott, but nevertheless he made the decision and I accepted it. One of these days, he and I are going to be rocking in chairs in Texas and talking about the good old days."

FOX News' Carl Cameron and Wendell Goler contributed to this report.