Second time around, and are we as excited about another royal baby? Maybe we ought to be. The history of the British Isles has been littered with younger royal siblings who have done much to shape today's monarchy.
William the Conqueror himself left England to his second son, another William, while the eldest inherited Normandy. Richard 'the Lionheart' and Henry VIII were both younger brothers. (So were Richard III and Charles I, less happily.)
Until the recent changes in the law gave a princess the same rights in the succession as a prince, it was usually about being a second son, rather than just a second child. All the same, Elizabeth I was a younger sibling, and Queen Anne too. North of the border, James V and his daughter Mary Queen of Scots are just two more of the many British monarchs with elder brothers who died in infancy.
In the bad old days of high infant mortality, any royal family needed an heir and several 'spares' - in the harsh but all too telling phrase. But even in more recent times, George V was born a second son. His elder brother, the scandalous Prince Eddy, died of pneumonia in his twenties. Then, famously, Edward VIII's relationship with Wallis Simpson brought his younger brother to the throne as the present Queen's father, George VI.
Even when they don't actually inherit the crown, several younger siblings have had a huge effect on the future of the monarchy. Back in the fourteenth century, John of Gaunt kept a steering hand on the country during the minority of his nephew Richard II - and then it was his bloodline that gave birth to the Tudor dynasty. When the Hanoverians came to the throne in the eighteenth century, it was as the descendants of Elizabeth of Bohemia, King James's second child and the romantic 'Winter Queen'.
So much for politics - but what about the personal side of the story? A telling photograph once showed the late Princess Margaret with a wry smile on her face, clutching a cushion on which were embroidered the words 'It isn't easy being a princess'. The question is, how much has changed today - and what kind of life we're going to allow this second Wales baby? Things should be changing - and not only because of a different social world, and a new, more modern, monarchy. There's also the fact that we're all living longer, with the royal family leading the way.
The royals never used to have careers, outside a very specific field - but it was the same for all the aristocracy. Women married, and men went to land management, the church (with charity as the modern equivalent), or else the military. It was also true, however, that the generations succeeded each other much more quickly. Our present Queen was 25 when she came to the throne - as was Elizabeth I, while Victoria at 18 was a baby.
By contrast, Prince Charles will be a senior citizen, and hasn't always found a waiting role easy. If the family trend continues, this new baby will never be second in line for the crown. Prince William - if not Prince Charles himself! - will still be on the throne when Prince George marries and sets up his nursery. Time for a fresh look, perhaps, at the range of roles we'll allow to even the most senior members of the royal family.
If the baby is a girl, it's going to be an excitement for everybody - from Prince Charles, who's said to be eager for a granddaughter, to the public, who've been putting all their money on a female baby. Analysts have declared that a princess would be worth many millions (billions!) more to the economy.
But there is a threat there, as well as a promise. There's no word in the dictionary that comes more loaded with expectation than the word 'princess'. Think romance, think fairytale, think Disney. A baby girl is expected to do wonders, over the years, for the British fashion industry. But what if she goes through a teenage phase of being round and spotty? What if she's a tomboy? In Princess Anne and her daughter Zara we've seen two royal women who've forged notable careers in the sporting arena, but neither of them rank so high in the succession - and neither of them were expected to carry Kate's, and Diana's, glamorous legacy.
If the baby is a boy, then the pressures are different - but the constraints just as great, maybe. If a career of military and charity work suits him as well as suits Prince Harry, fantastic. Everyone will be happy. Or content, if not excited, anyway. But if not, maybe the growing child, boy or girl, should be allowed to choose its own direction, and develop in its own way.
Then maybe - for the royals and for the rest of us - the changing world could be not just a challenge, but also an opportunity.