Princess Charlotte of Wales was born and named, it would be widely expected that she would have a brother who would have displaced her in the line of succession. It wasn't until years later that if became obvious that she would be her father's only child.
Same thing for her cousin Princess Victoria — not only would she have been expected to have a brother, but on top of that she had two uncles ahead of her in the line of succesion who could have produced children at any point in time. In fact, in the years after her birth her uncle William (IV) had a daughter (who given the family's lack of heirs was appropriately named Elizabeth, a "regal" name) and 3 sons who all died in infancy. It was telling of Victoria's litttle dynastical status that her parents were forbidden to give their daughter a queenly name (Charlotte and Elizabeth were their choices) and had to pick something "foreign" and unusual.
If William and Kate's child is a girl, it will be the first time in history that a Princess will be expected to be Queen at birth.
Drake" and you wouldn't officially refer to the President of the USA as "Barry", you can't have a "Queen Rebecca" (which isn't even a Christian saint's name). Like we've said, they'll have much more freedom to name the younger children.
When the Swedish Crown Princess and Prince named their daughter Estelle it was a pretty big controversy in Sweden, until they saved face by coming up with an obscure relative with that (foreign, non traditional) name — and the Swedish monarchy is nowhere near as important and traditional as the British.
Victoria's birth, the Duke of Kent proudly went around saying that his daughter was going to be the future Queen of England, and seeing as she was older than Princess Elizabeth of Clarence, I'd say that she very much was expected to become Queen at the time of her birth (with the demographic of stillborn children born by the Duchess of Clarence, I wouldn't bet that their hopes were to high by the time of Elizabeth's birth).
As for the names, the Prince Regent objected against her being named Georgina or Georgiana (much like he objected against Elizabeth being named either of the names), so therefore she was named after her godfather and mother, which really wasn't that odd in those days (Elizabeth was named Elizabeth Georgina Adelaide) and though they might've been slightly uncommon, I would hardly say it's a surprise that they named her what they named her.
If Kate and Will have a daughter the top names I believe will be:
Amelia, Cecilia, Gemma, Serena, Olivia, Louisa or Julia?
But if it´s a boy i have a strong feeling it might be a Jonathan, Victor, Alfred, Theodore or Joseph.
Charlotte's birth then later told a friend that he'd only ever had sex with his wife 3 times. No one would've expected a male heir from then on.
Prince Frederick was long since sperated from his wife, who was well past child bearing age anyway, and the DoC's wife was looking less and less likely to produce a live, healthy heir. So, no, it wasn't expected from the word go, but for the daughter of the fourth son- they certainly kept her in mind. Why else would the Prince Regent try to have much say in her name and her upbringing? And why else would Prince Edward have his heavily pregnant wife rush back to England just days before Victoria's birth?
ETA: Damn, missed shvibziks' response too! I agree with all she said!
I feel like there's all this hype for the royal baby's name, and some people are likely to be disappointed. As shivbziks said, the monarchy is quite traditional, and the name will likely reflect that. The first name is likely to be very traditional, and then the middles will most likely honor family members. As much as I would love to have William and Catherine pull a Victoria and Daniel and have a less traditional name, I highly doubt that will happen.
I think the "royal" baby name to watch for is Zara and Mike (This baby won't really be "royal" per se, but Zara is the granddaughter of the Queen). They'll be able to have a wackier name a la Peter and Autumn's Savannah and Isla.
The name is definitely going to be traditional but I hope they pick something that will surprise us!
I hope they'll think traditional but still out-of-the-box (the box in which George/Edward and Victoria/Elizabeth seem to be the safest bets). Personally I root for either Alexander, Arthur or Richard (and admittedly, I don't think Edward would be the worst name for them to choose), or Matilda, Eleanor, Mary or Adelaide.
On a different note, I think that Zara's baby might be a Philip/Philippa (with a strong emphasis on Philip because I think it's a boy :D). Zara's supposedly very close to her grandfather (like Anne is her father's favourite child), and Mike's dad is Phil. Plus, Zara's maiden name is Phillips, how perfect can it be?