Will Elton Perform at Prince William's Wedding Reception?
It will be Britain's biggest wedding since Charles and Diana's 30 years before - and preparations were already under way last night.
Royal aides, government officials, security chiefs and religious leaders have started outlining plans.
And just like with any other couple, there is the venue, best man, bridesmaids, guestlist and honeymoon to consider.
But this is no ordinary wedding and, though the date is not known, it will be declared a national holiday.
Up to two million wellwishers are expected to turn out to cheer the couple.
And the big day will be a perfect birthday gift for the Queen, who turns 85, and Prince Philip, who reaches 90 next year.
There is plenty of planning still to be done - but here is a glimpse at how this 21st century fairytale will be celebrated.
William's mother Princess Diana had five younger girls: Clementine Hambro, five, Catherine Cameron, six, Sarah-Jane Gaselee, 11, India Hicks, 13, and Lady Sarah Armstrong-Jones, 17, but Kate is older than she was when she wed.
Chief bridesmaid next year will most likely be Kate's younger sister Pippa, 26, helped by William's cousins Zara Phillips, 29, Prince Edward's daughter Lady Louise, six, and Lady Helen Taylor's daughter Eloise, seven.
Outsiders include members of The Sisterhood, athletes and dragon boat racers Kate trained with.
The most likely choice is Westminster Abbey, left, even though it was the scene of Diana's funeral, as well as the Queen Mother's.
The Abbey - where the Queen married in 1947 - holds around 2,000 guests, and senior courtiers are believed to have looked into a ceremony in the second week of August.
It is said William would rather marry in the 800-seat St George's Chapel in Windsor Castle, preferring a low-key ceremony like the wedding blessing of his father Charles and Camilla Parker Bowles in 2005.
However, royal protocol demands heads of state from around the world attend so St George's is simply too small. William is reluctant to use St Paul's Cathedral, hosting 3,500 people, because it was the scene of his parents ill-fated marriage in 1981.
Royalty including ancient Euro-pean dynasties such as Sweden, Spain, Norway, Holland and Denmark will attend.
Heads of state will be there although not some wives and first ladies. One exception may be US President Barack Obama who is likely to bring wife Michelle.
Celebrities could include singers who have performed for the Prince's Trust, such as Phil Collins, Sir Elton John, Sir Paul McCartney and Bryan Adams. Radio host Fearne Cotton may get a invite after interviewing the Prince.
Kate's family will sit at the front. Other guests will include school and university mates and armed forces colleagues.
William will give his bride a wedding ring made from rare Welsh gold - just like his father and grandfather.
All recent royal wedding rings have been made from the same nugget of Clogau gold given to the Royal Family in 1923.
William and Kate are certain to continue the tradition but will be able to choose the design of the rings.
The gold was extracted at the St David's mine in Bontddu, Snowdonia - only 50 miles from the cottage on Anglesey where the newly-wed couple will make their first home.
Royal grooms have a "supporter" than a best man and brother Prince Harry, 26, favourite, as Prince Andrew was Charles in 1981.
The boys have endured much together and both serve in the armed forces, but William also has a coterie of protective friends whose loyalty may be rewarded.
Here are the odds by Ladbrokes: 1/100 Prince Harry; 14/1 Princess Anne's son Peter Phillips; 33/1 One of closest pals the van Cutsem brothers; 40/1 Former housemate Fergus Boyd; 50/1 Thomas van Straubenzee.
William and Kate will continue to live at their cottage near the prince's RAF base in North Wales. It is well protected and offers them a great deal of privacy.
When they stay in London they will use his apartment in St James's Palace, below.
In the longer term, it is believed a house will be built for the couple at Harewood Park, a Duchy of Cornwall estate in Herefordshire, an hour's drive from Charles's Highgrove home.
After nine years together, the couple, both approaching 30, will want to start a family as soon as possible, producing the so-called "heir and spare" to ensure the royal succession.
The royal couple are expected to spend part if not all of their honeymoon in New Zealand after the Prince's hugely successful first foreign visit there in January.
It is predicted they will arrive in time for the Rugby World Cup, which starts there on September 9. The Prince is a huge fan of the sport both as a player and spectator and a Royal patron of the Welsh Rugby Union.
The couple may well also visit neighbouring Australia and, like William's parents, spend some time in the Highlands at Balmoral.
Issa, the fashion line of Brazilian designer Danielle Helayel, has become Kate's favourite choice.
She wore one of her dresses for yesterday's announcement and seems likely to commission a wedding dress, which could cost as much as £10,000.
However, there may be pressure on her to opt for a British designer as she is expected to fly the flag on her special day.
Bruce Oldfield would be an obvious candidate - he was a friend of Diana and has designed wedding dresses for Queen Rania of Jordan and Jemima Khan.
Or she could turn to Elizabeth Emanuel who made Diana's dress with her then husband David.
Outsiders include London-based Jenny Packham and Amanda Wakeley.
Smart money is on celebrity florist Rob Van Helden, who has previously provided blooms for Elton John's parties.
Prince Charles may also insist the occasion calls for flowers from his beloved Highgrove estate in Gloucestershire, which has Kate's favourite white lilies.
HAIR & MAKE-UP
Kate's hair will most likely be done by celeb-rity crimper Richard Ward, left, based in Chelsea, west London. He will get the best out of her rich chestnut tresses, while make-up artist Komal Singh could be called in to oversee her appearance.
The couple will have a team of officials to help them plan the wedding, including aides from Clarence House, Privy Council officials and Kate's family.
Jamie Lowther-Pinkerton, Private Secretary to Prince William and Prince Harry and press secretary, Miguel Head, could also help.
Royalty Protection branch SO14 will handle security and a wedding planner will handle cake, invitations, food and music.