Will Sun on Sunday rise after the News of the World goes?
The News of the World is about to be published for the last time but how quickly will its publisher News International launch a replacement? And, if it does, how different will it be from its predecessor?
News International seems unlikely to be without a Sunday tabloid for long, even though the News of the World brand has been badly damaged, and red-top newspaper sales are in steep decline.
Withdrawing from the Sunday tabloid market would mean giving its newspaper rivals an open goal to grab the News of the World's readers and advertisers, both in print form and online. Shares in the publishers of the Mail on Sunday and Sunday Mirror rose, after City analysts identified these as the likeliest beneficiaries.
Speculation has focussed on a Sunday version of the Sun, as the most likely replacement for the News of the World. Only last month, News International rejigged its management restructure, making it easier to introduce seven-day working across its two tabloids. The company has refused to comment, but the domain name thesunonsunday.co.uk has been registered.
How different would a Sunday version of the Sun be from the News of the World? That would depend on which elements of the old brand were deemed worth keeping.
The News of the World's stock in trade was exposing crime, and scandals about the rich and famous - often involving sex, drugs and money - and occasionally all three. Its "fake sheikh", Mazher Mahmood, and other undercover reporters lured a string of sports stars, politicians and junior members of the royal family into indiscretions, often secretly filmed (backed by claims of a "public interest" justification).
Last year, Prince Andrew's ex-wife Sarah Ferguson was filmed taking money from a News of the World reporter. A few months later the paper exposed spot-fixing allegations against the Pakistani cricket team. The paper won four prizes this year's British Press Awards - and has claimed that Mahmood alone has brought 130 criminals to justice.
Would News International hope to replicate this success with a Sun on Sunday?
Such investigations do not come cheap and are dependent on a close relationship between journalists and the police. Given the current inquiries - including allegations that the News of the World made large and illegal payments to police officers - this may not be a route the publisher wants to pursue.
Some think the Sun on Sunday would be more valuable as an online presence - attracting a new younger readership - than as a red-top tabloid newspaper. Even so, selling at £1 a copy, the News of the World still generates over £2.5 million a week in cash, which is not to be sneezed at.
The News of the World may not be the only casualty of the affair. David Cameron said the industry regulator, the Press Complaints Commission, had failed and must be replaced by a new system entirely, independent of the press and of government.
He said the PCC had been exposed as "ineffective and lacking in rigour" by the phone hacking affair and it would be for an inquiry to decide what the new system should look like. For once, the opposition leader Ed Miliband agreed, saying it had been exposed as a "toothless poodle".
The PCC has written to the prime minister welcoming the inquiry, but rejecting his analysis, saying the organisation should not be made "a convenient scalp" following the phone hacking scandal. It says: "The work of the PCC, and of a press allowed to have freedom of expression, has been grossly undervalued."
That may be so, but as the events of the week have made clear, the PCC has failed to convince the public that it's doing a proper job.