If William and Kate have a daughter she will take precedence over any later sons

Back in October, said BBC News:

Sons and daughters of any future UK monarch will have equal right to the throne, after Commonwealth leaders agreed to change succession laws. 

The leaders of the 16 Commonwealth countries where the Queen is head of state unanimously approved the changes at a summit in Perth, Australia. 

It means a first-born daughter of the Duke and Duchess of Cambridge would take precedence over younger brothers.

Which is just as well in view of today's news.

It will also avoid a situation I warned of earlier this year:

My second piece of advice is to urge them to change the law of succession so that males and females are treated equally and to do it quickly. 

The current position is logically indefensible (though, come to that, so is the institution of monarchy as a whole). And the demand for equal treatment for women is not going to go away. 

So the change should be made now when all the immediate heirs are male. That way it will not become a debate about individuals. 

Just imagine if William and Catherine have a daughter and then a son. The debate about changing the law of succession would then become intensely personalised. It would not deal with questions of gender equality or constitutional precedent, but with the personal qualities of two children. A public tantrum would lead to solemn articles about whether the thrower was fit to be king or should be passed over in favour of his sister. 

We are told that making such a change would be difficult as it would require assent from every Commonwealth country. But that is an argument for urgency, not one for doing nothing.

So well done to those Commonwealth leaders for pulling their fingers out. This was one of those questions where Conservative ends - maintaining the monarchy - required radical change to allow to continue in a changed world.

The Commonwealth leaders also voted to remove the bar on a Roman Catholic inheriting the throne. I fully expect this to cause all sorts of problem with the Church of England one day. Such fun!