It’s enough breaking news to make even an anchorman’s head spin.

Television is undergoing a sea change this season as a dozen famous television anchors and celebrities — whose shows are watched by more than 40 million viewers every day — are leaving their longtime perches.

To name a few, on Friday, Jim Lehrer ended his daily duties on the “PBS NewsHour”; on Monday, Scott Pelley replaced Katie Couric on the “CBS Evening News”; on Wednesday, Meredith Vieira will leave the “Today” show on NBC; and later this month, her former colleague Keith Olbermann will start a new show on Current TV.

By now, viewers may barely recognize their favorite shows and channels.

It seems like the most tumultuous time on the small screen in a generation, but much of the tumult is off the screen, in business meetings about how the media industry is transforming.

Although some of those departing, like Lehrer and Regis Philbin, are leaving their shows because of a generational shift, others are moving on because they want a bigger financial stake in their own brands. Couric, Oprah Winfrey and Glenn Beck, among others, are taking equity stakes in themselves, separating from the media conglomerates that have profited mightily from their star power.

On Tuesday, Beck became the latest to take the leap, announcing his own Internet network for subscribers. The promise is that different ways of delivering content, like cable, syndication and the Web, will prove to be more lucrative for star anchors and hosts — still largely an unproven proposition.

As the media industry recovers from the recession, millions of dollars stand to be made. That opportunity has given rise to what might be perceived as an Anchor Bubble, something akin to the dot-com bubble of the late 1990s.

“The changes have been nothing less than seismic — so seismic, in fact, that the next generation needs to work even harder to try to put the pieces back together or get some semblance of an audience,” said Jonathan Wald, who produces Piers Morgan’s nightly program on CNN. Morgan replaced Larry King in January.

Just as the Internet is emboldening stars, it is emboldening media companies: Comcast, which successfully bid Tuesday for eight more years of Olympic Games, intends to make more of the games available online, and Disney intends to turn its main website, Disney.com, into an online video destination not unlike Netflix or Hulu.

“We believe we have an opportunity to deliver content directly to consumers,” Bob Iger, the Disney chief executive, told investors last week.

Winfrey’s arrangement for her new cable channel, called OWN: The Oprah Winfrey Network, may be an inspiration for others: Her production company owns half of OWN, so if it is a success, Winfrey, 57, already a billionaire, could earn far more money than she did on an annual basis on “The Oprah Winfrey Show,” the 25-year-old broadcast talk show that ended last month.

All of these comings and goings, of course, hinge on consumers’ willingness to accept change and to follow their favorite hosts to new media homes. In an interview, Winfrey said she smiled when she read a viewer’s comment on an Oprah.com message board that said her move from broadcast to cable created no problem “that my changing channels cannot fix.” But Winfrey acknowledged that finding OWN on the cable lineup has been a big problem for some people, and said she wished more people were watching.

Couric announced Monday that she was creating a daytime talk show not unlike Winfrey’s for the fall of 2012. The fact that Couric, 54, owns the show with a partner made it an especially attractive proposition for her.

Similarly, Olbermann walked away from MSNBC in January for a job — and an equity stake — at Current, where he starts June 20, and Beck will leave Fox News at the end of this month. Beck will wholly own his new online network, GBTV, which will charge $5 to $10 a month.

Robust broadband Internet access and connected devices like cellphones and laptops have the potential to let stars “break away from the traditional content-distribution ecosystem,” said Richard Greenfield, a media analyst with BTIG Capital.

Of course, people like Olbermann and Beck never would have become stars without that very ecosystem. Only a few people have managed to start on their own on the Internet and parlay that into a prominent television presence.

Sweeping changes in the media industry have made this an especially stressful time for talent. For some, there is a more cautionary model in mind for the future: Johnny Carson, who rarely appeared in public after exiting “The Tonight Show” in 1992 and was said to be deeply unhappy. No stars this year seem to be taking that approach.

In the fall, for instance, Philbin, 79, is leaving his daytime talk show, “Live with Regis and Kelly,” after 28 years. “Time for the old guard to go!” Philbin said, laughing, in an interview last week.

But this does not mean he is retiring. In fact, Philbin went out of his way to say he was not. “I’m getting to the end of the line, and I thought, ‘Maybe I’d like to try to do something a little different,”’ Philbin said, declining to disclose any details about his next show or shows.

It may be easy to leave a television show, but it is certainly hard to stay away. Philbin’s friend, King, has acknowledged that fact in interviews, saying that his instinct on big news nights is still to head into the studio.

For some, Tom Brokaw is the model. He stepped down from “NBC Nightly News” in 2004, but he helms documentaries, writes books and offers commentary on NBC. “I more than keep my hand in, and yet I’m not chained to a desk,” he wrote in an email message Tuesday night.

Lehrer, 78, who had gradually reduced his role on the “News Hour” for two years before deciding to stop being a regular anchor, will continue to weigh in on editorial decisions, and will anchor on some Fridays.

Vieira, 57, who will be toasted by her co-hosts Wednesday morning, told “Today” viewers last month that “I’ve really had a great time, but time is one of those weird things — you can never get enough of it.” She said she wanted more time with her family.

Like King and Lehrer, Vieira will still have a part-time job: She is expected to meet this month with NBC News executives to talk about becoming a contributor to a prime time newsmagazine that NBC is creating.

© 2011 The New York Times Company