I would wish that, since they are a modern couple, that they would choose a decent traditional first name that
hasn't been used in the royal family's history yet. You know, the family could use the fresh injection of a new name. They could reserve the child's middle names for honouring (i.e. still preserve family tradition in a way), so that way, they would have the freedom to choose a first name that they like without being completely limited to names that are in the family only.
I'm really hoping that they will go that route. And if they do, I would love it if they had a son and named him
Rupert. A little prince
Rupert would be so darling! Not to mention that
King Rupert would sound very strong, too.