The question takes on a wider significance because yet more of these continuations are on the horizon. Sophie Hannah has been asked to rise to the challenge of Agatha Christie and Hercule Poirot; the first writer since Dame Agatha's death in 1976 to do so.
She knows what she is up against: anyone who imagines that Christie's crisp, plain style and precision plotting is easy to replicate is very wrong.
Elsewhere, the highly distinctive literary voice of Raymond Chandler is, with the blessing of his estate, being brought back next spring with Black-Eyed Blonde, a new Philip Marlowe novel. This bodes well: the author walking into Chandler's noir world is John Banville, a novelist deeply accomplished in exploring real darkness.
Conversely, there is the trick of helium lightness and exquisitely frictionless farce: next month sees publication of Jeeves and the Wedding Bells - a P.G Wodehouse "homage" by the versatile Faulks.
Here, the formidable challenge is not to sound like a fruity Thirties parody; advance word is that Faulks has done an uncannily good job and that his Wooster reads with affectionate authenticity.
Equally passionate are the Conan Doyle brigade. A couple of years ago, Anthony Horowitz's Holmes novel, The House of Silk, was the first continuation to receive the official blessing of the author's estate and reviewers paid tribute to the sincerity of Horowitz's tone.
Literary 007 has had a particularly lively - if artistically uneven - existence since the death of his creator, Ian Fleming, in 1964.
Even before he died, Cyril Connolly leapt in with a lethal word-perfect spoof - Bond Strikes Camp - in which the agent dons a frock to entrap a Russian spy. Conversely, 007 fan Amis, writing as Robert Markham in 1968, played it absolutely straight, with a Bond novel set in Greece involving a sadistic Chinese colonel who has a neat way with meat skewers and ears.
Fleming's literary agent Peter Janson-Smith thought highly of this work. "Amis could reproduce the Fleming style without making it look like parody," he said. "And very few could do that."
Following Fleming's death, Janson-Smith looked after his estate for years, stepping in to safeguard it under some unlikely circumstances.
In the mid-Sixties, behind the Iron Curtain, Bulgarian thriller writer Andrei Gulyashki decided to match his fictional hero spy Avakoum Zakhov against 007 in a mighty showdown. Naturally, the Communist won.
A British publishing house at this point showed an interest in publishing the book; and Janson-Smith, though quietly amused, had to take action. For the Eastern bloc to hijack the character of 007 without authorisation was one thing. To have Bond then defeated was going too far.
By the Eighties - as the garish films had all but overshadowed the original books - thriller writer John Gardner was awarded the chance to revive the fortunes of literary Bond.
He wrote a number of novels with somewhat naff titles - Win, Lose or Die, Death is Forever - that none the less gained a reasonable following. Next came Raymond Benson, with a penchant for even naffer titles - Zero Minus Ten and Never Dream of Dying.
But in recent years, the Fleming estate has hired rather more highbrow authors such as Faulks in order to preserve the authenticity of the Fleming tone.
Reviews were strong and - perhaps more pertinently - sales were spectacular. Recently, American Jeffery Deaver was commissioned by the estate to write contemporary Bonds; his first, Carte Blanche, was perhaps politely over-researched in British tics. In one passage, M finds himself thinking about The Two Ronnies.
In rather more classical terms, some resurrections can bring rewardingly fresh approaches for long-term fans. Venturing into the daunting territory of Jane Austen was the novelist Lynn Shepherd with her debut book Murder at Mansfield Park (published just before P.D James' Death Comes to Pemberley).
The idea of blending a gory whodunit with the Mansfield intrigues, Shepherd says, actually provided a means to look at Austen's work and characters in quite a new way; an exploration of the very engines of Austen.
Shepherd had to study very hard. "It was the language," she says. "Making sure I didn't commit gaffes. I researched every word that I had any doubt about. Austen, oddly, had a relatively limited lexicon. And obviously there were no violent deaths in her work! So for that I looked to Samuel Richardson - Austen's favourite novelist. A gold-mine for vocabulary."
Her intention, she says, was both to give an entertaining read, and also to hold a mirror up to the original.
"It could have been like trespassing on sacred ground," she says. "But I set myself the task of making sure I did it properly. These things matter to me. And obviously these books matter. I wasn't going to go trampling around."
The book was a particularly big hit in the United States, where Austen fans adored it. Shepherd also heard from readers who said it had encouraged them to try reading the originals for the first time.
This is another reason why literary estates are keen to have new authors revisit old classics: a flurry of interest in the original works.
In other words: ker-ching. It is inconceivable, for instance, that Faulks's new Jeeves novel won't make new readers seek out Wodehouse's originals.
And literary continuation is nothing new either. Perhaps the finest example - a novel arguably as good as, if not in some ways better than, the original - is Jean Rhys' 1966 Wide Sargasso Sea.
Inspired by Charlotte Bronte's Jane Eyre, this was the story of the first Mrs Rochester, set in the Caribbean; an extraordinarily powerful work of alienation, delirium and insanity.
Shepherd is currently working on a reimagining of Dracula. She is acutely aware of her responsibility to the readers.
On the subject of resurrections as a whole, she says: "With any of these continuations, it is a great challenge: the skills involved, the ventriloquism, to get inside someone else's creation. Dickens has that brilliant phrase 'recalled to life' and that is how I think of it. The characters are not marionettes to be manipulated. They have to be recalled to life, so that they can live on the page."
