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 blasé 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."