DIANA is the early frontrunner among punters for a name for Kate Middleton's Royal baby - well before we even know whether she is having a boy or a girl.
Bookmakers say Prince William and his wife Catherine will name their baby after a close relative.
Betting chains are offering odds on the baby's name, its sex, weight, godparents, hair colour and even the time and day of birth.
The baby will be third in line to inherit the throne, meaning a King John II or Queen Anne II could be possible.
Early favourites in UK are Frances and John at 9/1, with Charles, George and Victoria 10/1, followed by Anne, Diana, Philip, Richard and Spencer at 12/1 and Henry, Mary and Sarah at 14/1.
News of the Royal baby broke in the early hours of this morning (Australian time) with congratulations flooding in via Twitter and from politicians around the world
A spokesman said the Queen and Duke of Edinburgh, the Prince of Wales and members of both families are delighted with the news, with David Cameron tweeting: "they will make wonderful parents".
The palace said Kate Middleton was admitted to the King Edward VII Hospital in central London with acute morning sickness, known as hyperemesis gravidarum, and is expected to stay in hospital for several days.
A spokesman said: "As the pregnancy is in its very early stages, Her Royal Highness is expected to stay in hospital for several days and will require a period of rest thereafter."
It is understood that the pregnancy has not passed the 12 week point and today's announcement was prompted by the Duchess's medical condition.
What should Wills and Kate name their Royal baby?
For women with hyperemesis gravidarum their vomiting can be so severe they cannot keep food or liquid down.
The condition usually continues past the first three months of pregnancy and can pass by week 21, but may also last longer.
St James's Palace confirmed that William is by his wife's side in hospital but would not comment on whether he travelled with her to hospital.
Kate made the journey from Bucklebury in Berkshire, where her parents Michael and Carole Middleton live, and it is thought she spent the weekend with them.
The Duke and Duchess of Cambridge's baby will be born third in line to the throne and a great grandchild to the Queen.
Thanks to the proposed radical shake up of the monarchy's rules of succession, the sex of the royal infant will not determine whether he or she wears the crown.
This baby will be a future king or queen regardless.
In October 2011, David Cameron announced that the 16 Commonwealth countries where the Queen is head of state had agreed to give female royals the same rights of succession as their brothers.
Under the ancient rules of male primogeniture, first born royal daughters in direct line to the throne were leapfrogged by their younger male siblings.
The last time a still-serving monarch got to meet a great grandchild born in direct succession to the crown was nearly 120 years ago.
Queen Victoria, who reigned until 1901, was still sovereign when her great grandchild Edward VIII, who later abdicated, was born third in line in 1894.
His brother George VI was also born in Queen Victoria's lifetime, arriving fourth in line in 1895.
The last great granddaughter of a still-serving sovereign born in direct succession on the male line was their sister Princess Mary in 1897.
William and Kate's baby will be the great great great great great grandchild of Queen Victoria.
When the newest addition to the Royal Family arrives, Prince Harry, the baby's uncle, will be bumped down the line of succession to fourth place.
Twitter abuzz over baby news
Twitter is polarised over news of Kate Middleton's pregnancy announcement.
Some tweeps are bubbling over with joy, while republicans bubble incandescently over the special treatment the foetus is currently receiving just for being a "#royalbaby".
Meanwhile, some commentators, like @amolrajan, are torn between simple joy at the news of new life and the opportunity to argue that the royals should immediately renounce their titles and go live in a hovel in Wales.
Here are some of the funniest, weirdest, loveliest and most controversial tweets so far.
@soukici: "In stark contrast to the rest of the economy, the bunting industry is having a booming start to the decade."
CarlaDobson: "Guardian is liveblogging the royal baby news wonder if they'll keep it up for six months"
@JeromeTaylor: The "worst rated" comment on MailOnline's royal baby report is hilarious http://twitpic.com/bisizs
@LisaBeesa: "The first sentence makes me giggle. Mainly because that's totally my reaction to the news! http://vnty.fr/XiDSBA"
@BrooklynDecker: "I hope Royal Baby and Blue Ivy Carter become best friends."
@TH3Consequence: "Already sick of the half blood prince royal baby jokes, snape wouldnt want to be associated with royals stop giving their baby his name"
@Joe_Whit: "Can someone save all the royal baby articles & then when it's grown up weird it out with how big the news of its conception was?"
@Commodity_Bull: "the royal baby has nothing on an American made iMac"
@Bourb0ns: "When the royal baby is born they better do the whole Lion King routine with it.
@YahooOMGUK: "The Jubilee, Olympics and NOW#royalbaby, has this been the best year EVER for Britain?!"
@Hel_374: "With all this excitement I have to keep reminding myself that it's not actually me that's pregnant"
@sophielelawrie: "And now a royal baby!!! This is a serious contender for the best Monday award"
@SeanWHughes: "What if it's twins? They should keep one under wraps - would come in very handy."
@George_E: "what we all want to know is, will she keep it? It could really interfere with her career."
HOW BUZZFEED TRANSFORMED THE ROYAL NEWS
In a way that only Buzzfeed can.
First they quote the Palace: "Their Royal Highnesses The Duke and Duchess of Cambridge are very pleased to announce that The Duchess of Cambridge is expecting a baby. The Queen, The Duke of Edinburgh, The Prince of Wales, The Duchess of Cornwall and Prince Harry and members of both families are delighted with the news. The Duchess was admitted this afternoon to King Edward VII Hospital in Central London with Hyperemesis Gravidarum. As the pregnancy is in its very early stages, Her Royal Highness is expected to stay in hospital for several days and will require a period of rest thereafter."