Prince William Wedding Mystery: Royal Watchers Search for Clues

VIDEO: Comparing Princess Diana and Kate Middletons similarities and
WATCH Kate and Diana: A Tale of Two Engagements

Barely 24 hours after Britain's Prince William and Kate Middleton made headlines the world over by announcing their engagement, the chorus of congratulations has been replaced by another international obsession: When, where and how will the wedding happen?

Will it be an April wedding? Maybe as early as March? Bookies are reportedly not taking bets on July. But where? Westminister Abbey is a likely location. Or somewhere completely new?

With few facts to go on, royal watchers and gossip-lovers alike are grasping at anything that could be a hint of the wedding that some are predicting will be watched by billions of people.

"There's a lot of speculation that it's going to be a summer wedding but I think it's very telling in the announcement that the palace put out yesterday that it could be a spring wedding," royal expert Katie Nicholl told "Good Morning America" today. "And royal engagement announcements by tradition are short. So I wouldn't rule out seeing something perhaps as early as March or April.

"And June is the month that's being batted around because it's the month that Prince William turns 29 ... that birthday date could be very significant," Nicholl added.

Within hours of the announcement, and Middleton's appearance wearing the late Princess Diana's famous sapphire and diamond engagement ring, orders for replicas of the ring exploded, crashing jewelry websites.

"I called my wife and said, 'Honey, I'm not coming home tonight," New York jewelry company CEO Michael Arnstein told the Canadian Press. "We're in a frenzy. This is changing our business overnight."

Tuesday's announcement was followed by visible sighs of relief from the happy couple, as they had been keeping the secret not just from the public, but from their own family for months.

Only the couple and Middleton's father knew they were to be wed. Queen Elizabeth had not been told nor given her permission until days before the announcement, Nicholl said.

The queen said she is "absolutely delighted" for the couple, Buckingham Palace said hours after the announcement.

Like the queen, Middletons' parents, Michael and Carole Middleton, said Tuesday they too were "absolutely delighted."

'It's About Time.' Royal Engagement Announced

Eight years after the couple met, Prince William appeared with Middleton for the first time as an engaged couple Tuesday.

"The Prince of Wales is delighted to announce the engagement of Prince William to Miss Catherine Middleton," a statement from Clarence House early Tuesday read.

Prince William, 28, asked Middleton, also 28, to marry him while the two were on vacation in Kenya last month, the statement said.

The happy couple appeared for the first time for reporters arm-in-arm before a barrage of camera flashes, Middleton wearing the famous engagement ring worn by William's mother, the late Princess Diana.

"He's a true romantic and we had a wonderful holiday in Africa and it was out there in a very quiet lodge and it was very romantic and it was very personal time for both of us," Middleton said.

In an interview with Britain's ITV News' Tom Bradby, who told "GMA" the interview was "terrifying," Middleton said the proposal came as a surprise, despite years of public speculation that the couple would wed.

"We were out there with friends, so I really didn't expect it at all," Middleton said. "It was a total shock when it came. Very excited."

The announcement came to the elation of Britons, many of whom viewed the engagement as a seemingly inevitable yet unreachable moment. Within 25 minutes of the announcement's posting on the royal Facebook page, more than 1,400 people "liked" the news. The numbers have since increased.

"It's about time! Congrats," one commenter wrote, a sentiment echoed by hundreds of others.

The Long Courtship

The two met nearly a decade ago while students at the University of St. Andrews in Scotland. The relationship garnered some controversy because Middleton does not come from royalty and royals are generally expected to wed other aristocrats.

William said the two were friends for more than a year and lived as flatmates. "It blossomed from then on," he said. "We had lots of fun. ... Same interests. She has a really naughty sense of humor."

When asked why it took so long to propose, a beaming William quipped, "I also didn't realize it was a race, otherwise I probably would've been a lot quicker.

"We have a great fun time together," the prince told reporters. As for the ring, William said, it, like Kate, was very special to him.

"Well as you may recognize now, it's my mother's engagement ring and it's very special to me, as Kate is very special to me now as well. It was only right the two were put together," William said. "It was my way of making sure mother didn't miss out on today and the excitement and the fact that we're going to spend the rest of our lives together."

Diana received the ring from Prince Charles after the two were engaged in 1981. At the time, the sapphire ring, which is surrounded by 14 diamonds, cost 30,000 pounds, or about $47,500 at today's conversion rate.

"I had been carrying it around in my rucksack for about three weeks before [the proposal]," William told ITV. "Everywhere I went, I was keeping ahold of it, cause I knew if this thing disappeared, I'd be in a lot of trouble."

"It's beautiful," Middleton said, as she showed the ring to ITV's camera.

While Middleton is now wearing Diana's ring, William said, she won't be in his mother's shadow.

"There's no pressure," he said. "Like Kate said, it is about carving your own future. No one is trying to fill my mother's shoes. What she did was fantastic. It's about making your own future and your own destiny, and Kate will do a very good job of that."

William said he didn't know where to start when asked why the couple was apparently so loving, but said she makes him laugh. For her part, Kate said William was very supportive of her.

William and Kate broke up briefly in 2007 but were back together within months.

Prince William is second in line for the throne, after his father Charles, Prince of Wales. Prince William's mother was Diana, Princess of Wales, who died in an auto accident in 1997.

The royal couple plan to live in north Wales, where Prince William will continue his service in the Royal Air Force, the statement said.

ABC News' Nick Watt, Sarah Netter, Jason Volack and Bradley Blackburn contributed to this report.