Royal Wedding Planning: The Dress, the Guests, the Bachelor Party?

Details of much-anticipated nuptials leak.

Dec. 1, 2010— -- Less than five months until all of Great Britain, and much of the world, comes to a standstill for the wedding of Prince William and long-time girlfriend Kate Middleton, details of the much-anticipated nuptials, from the likely dress to potential party plans, have emerged.

Common perception says that the royal couple has had a few months of official planning for the big day, but according to royal expert Katie Nicholl, the couple could have made a "secret pact" for marriage as far back as 2007. "Kate wanted to know she's not going to be waiting around forever, and William gave her his assurance," Nicholl told "Good Morning America." "Privately, friends were saying that they were as good as engaged."

Despite potentially years of planning, key details surrounding the wedding remain shrouded in secrecy, though that hasn't stopped the rumor mill.

Of principal concern for Kate is the choice of attire. A front-runner to design the dress is Bruce Oldfield, a British fashion designer who has clothed celebrities and royalty alike, including William's mother, the late Princess Diana.

The next piece of the puzzle is the guest list. Westminster Abbey can hold nearly 3,000 guests, and getting a ticket to the big event is no sure thing for even those close to the royal family.

Sir Elton John, a favorite of Prince William's late mother, has declared that he will "probably" perform at the royal wedding. According to the Daily Mail, John told Radio 2 presenter Steve Wright of his prediction before joking, "I'll probably be busking outside."

"There's no wedding planner," Nicholl explained to "Good Morning America," "Literally, there are four people overseeing this entire operation." The ceremony promises to be a traditional affair by most measures, but the couple look to make the event their own. "This couple will inject some modernity, a breath of fresh air," Nicholl said.

According to another royal expert, the affair will include the usual pomp and circumstance, but it won't produce blind spending, however. "There are constraints involved," former Buckingham palace spokesman Dickie Arbiter recently told "Good Morning America."

"William and Kate are going to be aware they're under the microscope in terms of costs."

While those pending details will continue to be of great concern for Kate, the matter of William's bachelor party could also be a cause for sleepless nights. William's brother, Prince Harry, is reportedly organizing the affair and is said to have hip-hop royalty Snoop Dogg as the headlining act. The rapper has even written a single, entitled, "Wet," specifically for the occasion.

What is set in stone in the location and date.

Westminster Abbey comes as no surprise to royal insiders. Steeped in more than a thousand years of history, the church has long been associated with the royal family. It was there that the coronation of Prince William's grandmother, Queen Elizabeth II, was televised to millions around the world in 1952. But the location is perhaps best known as the place where Prince William said his final goodbyes to his mother, the late Princess Diana, at her funeral in 1997.

The date itself, April 23, 2011, will be an extra national holiday, falling in the same week as Easter Monday, giving millions of workers a three-day week to either retreat from or take part in the festivities.

It's just another reason for Britons and citizens the world over to keep a watchful eye as details continue to emerge.

Couple Announces Engagement, Media Frenzy Follows

The couple announced their engagement last month. The queen said she was "absolutely delighted" for the couple, Buckingham Palace said hours after the announcement.

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

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

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

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