So, the government have quietly announced that from now on, daughters of the monarch will have the same rights of succession as sons. That is, if William and Catherine's first-born is a daughter, she will become queen ahead of any younger brothers she has.
As a matter of principle, this is something that is long overdue, even if it doesn't really affect anyone currently living. (Depending on how it is worded, it may mean that Anne and her children move up the list, while Edward and his children move down... but barring a major event, neither of these two were ever going to be crowned monarch anyway.) So, on the face of it, this is a good move.
It does rather beg the question of why the eldest child should become monarch anyway. Why Charles, and not Andrew, or Anne, or Edward? After all, the sex of a child is essentially just a matter of probability, and the birth order is likewise just a matter of probability. The eldest child is not automatically in any way a better as a candidate as monarch. If we're eliminating one accident of birth as a criterion for becoming monarch, why not another?
So perhaps when the monarch dies, the surviving children should draw lots to determine who becomes the next king or queen. Or, indeed, perhaps we should have an election.
But, of course, it's actually a very short jump from that to the ultimate step along this path - the elimination of the monarchy entirely. After all, being born a prince rather than a pauper is just a matter of an accident of birth. Being born to a rich family does not automatically make you a better candidate for monarch than anyone else.
(And I say all this despite not actually being anti-monarchy. In principle, I would prefer a republic. But in practice, I can't see any better solution, especially given the caliber of politicians we have currently.)
It's a very dangerous game, adjusting the rules for succession. Because as soon as you make any change, you open the door for making any change.