Piers Morgan was not in a shy mood. He rarely is. But as the former tabloid editor promoted his new CNN talkshow at a press event in Los Angeles last week, he had extra reason to celebrate.

Morgan announced his first guest interview – and it was a big one. Oprah Winfrey, the doyenne of American television, had already sat down for two hours with him. Suddenly the idea of Morgan – still a little-known foreigner to most Americans – stepping into Larry King's shoes did not seem so shocking.

"I defy any of you to watch my first show and not enjoy it," he told the assembled pack at the Television Critics Association event. "I think it was a great interview and I think it will absolutely encapsulate what I'm trying to do."

But Morgan has more than just Oprah to be pleased about, and the American viewing public has more than just Morgan to look forward to when it comes to British faces and shows on its screens.

He is indeed in the vanguard of a renewed British invasion of US TV, with a rash of imports and remakes; whether actors, presenters and journalists or the shows themselves. "This is not just a mini-trend. This is a maxi-trend," said Bob Thompson, professor of popular culture at Syracuse University in New York.

Along with Morgan, whose first show airs on 17 January, the British invaders are advancing across the TV landscape. There is the high-profile import of Downton Abbey, the period drama that will introduce American viewers to the aristocratic Crawley family and their household when it appears on the PBS network.

Then there is a rash of remakes. MTV is busy adapting the teen comedy drama Skins for its own youth audience. It will debut on US TV on the same night as Morgan's show with the Oprah interview. Meanwhile, Shameless is also getting an American makeover on the Showtime channel. The jet black comedy about the Manchester underclass is being remade and set in Chicago with acclaimed actor William H Macy in the role of drunken layabout patriarch of the good-for-nowt Gallagher clan.

Later in the year, Morgan will have his status as America's brashest Brit challenged by a man already known to US audiences through his acerbic judging on American Idol: Simon Cowell is taking The X Factor to the States this autumn, and is reportedly hoping to take Cheryl Cole with him.

Finally, one new show is dealing specifically with the question of Anglo-American television ventures and transatlantic communication. Episodes is a British-American co-production about two British writers who take their hit sitcom to be remade in America, only to have Friends star Matt LeBlanc (playing himself) miscast in the lead role.

This British wave has not gone unnoticed. The influential New York Times television writer and critic Alessandra Stanley called it a "Britishification" of American television. Her article was headlined: "Sincerest forms of flattery for British shows."

But what do the Americans want with all this old country talent? The answers are as varied as the projects. The decision by PBS to broadcast Downton Abbey fits in with an age-old trope of showing period British dramas on America's not-for-profit television network. It fits with a cliched and ageing view that still believes British accents, acting and writing to be classic, and more intelligent than US equivalents. That may also explain why Morgan is able to become a hit in the States. In Britain he is known as a tabloid chancer, yet in America his English vowels and quick quips can turn him into a charming wit. "It goes deep into the American cultural heart that when you hear people speaking in British English, they are smarter than you unless proven otherwise. That is starting to drop away but it is still powerful," Thompson said.

The analysis however does not hold up to remakes like Skins and Shameless. Here, some of the attraction is the dark and gritty nature of the British subject matter. Many television executives and critics admire UK shows for being able to push the boundaries on issues of sexuality, violence and class in ways that the vast amount of mainstream American television cannot. "One reason British scripts stand out is that they are brutally candid and callous about sex, race and class," Stanley wrote recently.

By remaking a cutting edge British show, producers are able to slip in topics, subject matter and settings that would normally make senior network executives nervous. It would be hard, for example, to pitch the American version of Shameless by itself. But call it a remake of an acclaimed and successful British original (with a built-in cult fan-base) and suddenly commissioning a show about a Chicago white trash alcoholic man sounds attractive.

The process of remaking the British shows can hew close to the original. With Skins, MTV has embraced its raunchy content when it comes to sex and drugs. It has also copied the methodology of the British original, by using a group of teenagers as consultants to make sure the language and feel of the series is as authentic as possible. It is already generating a good critical buzz. "US Skins packs the punch and poignancy of the British original," declared the AfterEllen cultural blog. "Skins wins where Gossip Girls failed," opined the Huffington Post.

Yet it comes with the territory that British shows pass through a cultural curtain as they cross the Atlantic emerging as something of a different beast.

The makers of the US versions of both Shameless and Skins have admitted that they have had to tone down both language and content. Even Downton Abbey – shown as an original – has been repackaged into a different number of episodes for an American audience, although partly because it has been shorn of commercial breaks.

There is a long history of such changes. The Office came to America in a form very close to the original British version in its first few episodes, even sticking to almost the same script. Yet it steadily moved off on its own path. Now, as the American version passes into its seventh season, it bears almost no resemblance to its the British original.

Some of the most fondly remembered shows of American television history are remakes of British shows. All in the Family dominated the sitcom landscape of the 1970s, and was an adaptation of Til Death Us Do Part. The US show's protagonist, Archie Bunker, was once named the greatest American TV character of all time. Three's Company was a huge hit in the early 1980s, and was a remake of the British show Man About the House.

But predicting success is not easy. Sometimes sticking to the original can lead to disaster. The hit UK series Coupling was remade in the US and kept to almost exactly the same scripts, characters and plots. Practically the only American thing was the accents.

Yet it was a terrible flop and remains a cautionary tale for any budding TV executive. And if that example doesn't dissuade, the catastrophic remakes of Fawlty Towers, The Thick of It and Red Dwarf might just do the trick.

Experts admit that, far from being an exact science, taking something British and making it into a success in America is more like voodoo. "Nothing in TV is an exact science before the fact. It is alchemy. It is show business. You might as well consult the entrails of a chicken to see if something will work or not," said Thompson.

So which British shows will be a hit? Will Morgan turn one of the most high-profile slots in American television into a little outpost of England? Could the States swoon over Cole's Geordie vowels? The truth is that no one knows. Downton, Skins and Shameless could take off and become classics. Or they could sink without trace. Morgan could become a star, like King. Or he could fizzle out and fade away.

He, of course, was having none of that. As he continued relentlessly plugging the new show, the self-promoter par excellence was all bravado, assuring would-be guests that his Britishness would be a boon to them.

"Guests have a choice of a safe, easy five-minute ride [on rival shows]… or they can come on for an hour and joust with an annoying Brit and, if they succeed, be the toast of America," he claimed. "That's got to be a huge sales pitch, doesn't it?"

It remains to be seen if that patter will work in America. But in the crazy, unpredictable world of US television, it seemed as good a strategy as any other for a Briton trying to make it big.