"We don't really have a princess here," said Kathy Gitlin, an elementary school teacher in Connecticut who was thrilled to hear that Kate is with child. "I'm an Anglophile, I love England, and I think it's wonderful that two people in love wanted to get married and start a family. It's great."
There are several reasons for the American public's pleasure in Kate's news, manifested not only by the good wishes sent by President Obama but also by the breathless news coverage and the general good will toward the actually not-so-young young couple, who have both now reached 30.
First, and least complicated, is the fact that Kate seems a likeable and sensible young woman who married one of the world's most eligible bachelors without letting the power, prestige and A-plus jewelry go to her head.
Then there are the long ties between the two countries, so alike and so maddeningly different.
When Americans proudly declared their independence, they swore off sovereign kings and queens forever, yet several centuries later they find themselves drawn to the royals' pomp and pageantry, embracing the more colorful aspects of a system whose substance they had eagerly overthrown.
Finally, hardest to quantify, is the fading, almost ghostly, image of Princess Diana, who died so young. Americans want Diana's sons to flourish, and Kate seems to have made William very, very happy.
"I remember when Diana died, it was such a shock," said Gitlin, 52. "No one can ever take her place, but it's nice to have another person, someone this generation can look up to, and someone who William can love."
There's no doubt that many Britons are thrilled as well, and the country's embattled tabloid press certainly views a royal pregnancy (at Christmastime no less!) as a surefire circulation booster and a welcome diversion from a series of press scandals.
But some on Monday expressed a rather blasť attitude to the prospect of a new generation of Windsors seemingly bound for the throne. In the chill of early evening in north London's Camden market, young couples strolling among the stalls received the news of Kate's pregnancy with a shrug.
"I'm happy for them, but I don't really care," said Enya Lonergan, 19, who was visiting from Canterbury, south of London, with her friend Will Nichols, 20.
They could muster little enthusiasm for the news, noting that they had little in common with the royals, particularly in these bleak economic times.
"I don't think about them," Nichols said, adding that — naturally — he'd send them a gift. Or not.
Others said they were not interested and questioned the need for a royal family in the 21st century.
"I don't think it's a good thing," said Stephen Jowitt, 63, as he ambled down Camden High Street. "It reinforces a class system."
The news did provide a boost to one of Britain's national pastimes — finding new ways to wager money. Bookmakers are now taking bets on the gender of Kate's child, what the infant will be named and the color of his/her hair.
Joe Crilly, a spokesman for the William Hill bookmaker, said a high level of betting interest is expected, with favored names including Diana, Philip, Elizabeth and Sarah.
In America, ABC News even offered a poll, asking people to rate likely baby names.
Baby thoughts have been found in some less-than-fully-credible supermarket tabloids for months. They've been trumpeting "stories" about Kate's pregnancies for months, without any apparent basis in fact.
But that didn't keep the public from gobbling them up — the British royals, with their haughty glamour and slightly tragic air, have long captivated Americans.
"I'm always looking for any news of William and Kate," said 19-year-old Stacy McFacken, a clerk at a grocery store in Mentor, Ohio, in August when a number of tabloids offered screaming headlines about Kate's purported pregnancy.
"There's nothing like this in the States," she said. "It's just like all the fairy tales we read about as kids. We all want to be Kate."
Word of Kate's condition, including her hospitalization for complications, was top news on websites throughout the world. Her condition requires specialist treatment but if diagnosed early, it is unlikely to have long-term consequences for the mother or baby, and does not raise the risk of a miscarriage.
But while the parents might be anxious, world leaders stepped in to wish her well. The news was featured prominently on front pages in Argentina, India, France, South Africa and other countries. It sent Twitter into a tizzy, with the hashtag "royalbaby" trending worldwide and used more than 28,000 times in the first few hours following the official announcement. U.S. media websites such as People, Vanity Fair and the Daily Beast provided extensive coverage, with the Huffington Post launching a live blog to track developments.
"The whole wide world is excited," said Shao Hua Huang, a surgical nurse who practices in New York and Connecticut. "We're really happy for her. It's because of England and all the tradition. We Americans followed in their footsteps."