I think that they're afraid the extent of their censorship of the news will get out, and everyone will be pissed off, because they've been pushing the notion of free press for so long.
This whole "free press" thing.... wadda loada shite. You should see how badly the news in Canada is censored. And people think their free... *facepalm*
The UK press is amazingly free. Other than libel cases in court they are entirely self regulated.
That element should not be disregarded though, it was the Guardian, as part of the UK press that chased and took this story into the public eye amongst much pushback. The response should hopefully not be about strict regulation but rather overall ownership and competition.
People have said frequently that Murdoch and News Corp shoudn't care about the NotW because it is such an insignificant part of their revenue. That's true but it was a very significant part of their political influence as the most read paper in the land. The views of the paper, the apparent threats to polticians he can't get on regulated TV. TV makes the money but when the TV business was losing $2m a day it was the newspapers that rescued it with postive reviews of the shows, free ads and even free dishes. The vast profits of BSkyB could not have happened without the papers.
This is a frequent tactic in business, Tesco cheap baked beans lose money but get people in the shop, all of haute couture in fashion makes no money. It's brings people in, Glamour magazine say the show is a success and people buy the belts and wallets that they can afford with Louis Vitton written on them, it sets an agenda for another line of the corporation to make money.
There's the myth of Murdoch's sentimental love of newspapers, his ownership of the Times created loads of middle class cricket fans to sign up to his sports channels. The direct profit of NotW isn't that relevant compared to its influence and editorials. Even Hugh Grant said they laid off him with with the Divine Brown story because he was starring in a Fox film at the time. It was The Mirror that got the exclusive and ruined him.