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 recognise their favourite 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 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, the search is on for the next big thing, and for equally big ratings. ?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 programme on CNN. Morgan replaced Larry King in January.

Just as the Internet is emboldening stars, it is emboldening media companies: Comcast, which announced its successful bid on 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 favourite hosts to new media homes. In an interview, Winfrey said she had 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 line up has been a big problem for some people, and said she wished more people were watching.

Couric announced on 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 on 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.