Consider, for example, the well-received BBC drama Sherlock. While I was surprised by how much of Arthur Conan Doyle's original the writers managed to retain in an update that is on the whole clever and entertaining, the source material shows its age nonetheless.
There are constant reminders that the "Great Detective" above ordinary human concerns, passions and connections is a less convincing (and less acceptable?) figure than he was a century ago. Holmes is certainly looked at as rather more of a crank than a wonder by the cops he works with, and the fact reflected in a weakened self-assertion. Instead of confidently defending to Watson, and the reader, his ignorance of so elementary a fact as the Earth's revolving around the sun (as he does in the original tales), this bit of information is presented only as something Watson has let slip on his blog, and offers no answer when one of his more disdainful colleagues asks if this is really true. Holmes' sexuality also draws from the other characters speculations and commentary that never appeared in the Victorian source material. (And, one might add, Holmes has been turned from a cocaine user into an ex-smoker who simply slaps on extra nicotine patches when faced with an especially puzzling problem, a tobacco habit, it would seem, less acceptable today than a coke habit was over a century ago.)
Holmes' nemesis Moriarty, far from the Napoleon of Crime he is made out to be in stories like "The Final Problem," seems rather small fry. Charles Stross explained the reason for that in the afterword to his novel The Jennifer Morgue when he observed that:
The perfect criminal, should he or she exist, would be the one who is never apprehended . . . the one whose crimes may be so huge they go unnoticed, or indeed miscategorized not as crimes at all because they are so powerful they sway the law in their favor, or so clever they discover an immoral opportunity for criminal enterprise before the legislators notice it . . . When the real Napoleons of Crime walk among us today, they do so in the outwardly respectable guise of executives in business suits and thousand-dollar haircuts . . . I'm naming no names . . . [but] They have intelligence services! Cruise missiles!Certainly such views were not unknown in Doyle's time, but it may be that pop culture has since more thoroughly caught up with political consciousness (in spite of all the setbacks the latter has had these three past decades).
These significant differences in how we look at the protagonist and his nemesis aside, there is also the matter of how we look at their setting. Holmes' London was the world-city of its time, the political, commercial and cultural capital of a global empire that covered the map in red and ruled a quarter of humanity directly, the center of world finance, and much else besides. Not only is it the case that twenty-first century London enjoys no such position, but it might be said that no city on the planet does. (Those who might imagine an American city as a logical successor, for instance, would have to consider the division of functions between New York, Washington D.C. and Los Angeles, greatly complicating an attempt to find an equivalent.) The stage on which Holmes plays his part is diminished not just by the loss of that mystique, but also the disappearance of the opportunities for building that an Imperial London afforded for the Great Detective (whose services were sought by government ministers and crowned heads, as in "A Scandal in Bohemia"; whose adventures sometimes had serious implications for international politics, as in "The Naval Treaty"; whose career, in short, contained much that might only happen in the dominant international center of its day). And of course, there is the romance of the gas-lit, cobblestoned predecessor to today's metropolis, which Doyle's work is so famous for evoking. That, too, has no equivalent today.
That the show works as well as it does in spite of such diminutions is a testament to the strength of Doyle's original concept, and the talents of those involved in its most recent on-screen realization.