Now it's all about the details: The dress, the date, the venue - and who's going to pay.
Prince William and Kate Middleton sat down with advisers on Wednesday to begin planning the royal wedding that some Britons have waited years to see - and the British media settled in for months of juicy speculation.
The second in line to the throne and his long-term girlfriend will marry next spring or summer, but they haven't announced a date - some say May is likely, others August - or a venue. Westminster Abbey or St. Paul's Cathedral, where William's parents Prince Charles and Princess Diana married in 1981, are considered the front-runners.
A royal spokesman said the couple "spent the morning in meetings with household staff about the wedding" and would be closely involved in organizing all the details.
"It's very much their day like any other couple, and they will make the decisions all the way through - they want the day to be enjoyable for everybody," he said, speaking anonymously in line with palace policy.
But others will also have a say. Palace officials said an announcement of date and venue would be made "after other members of the royal family, Mr. and Mrs. Middleton and the government have been consulted."
It was too early to estimate its cost or how much the taxpayer will have to stump up - a touchy issue at a time of widespread budget cuts and austerity measures across Britain.
"I think it is just silly to ask us to pay for the wedding. We wouldn't ask them to pay for our wedding, so why should we foot their bill?" said Anna Simons, 35, an IT consultant from Hammersmith. "It is their wedding, not the country's."
The spokesman for William's office said "the couple are mindful of the current economic situation." He stressed that the wedding would not be a state occasion - unlike the one for Charles and Diana - because William is not the sovereign or the heir to the throne. "However, given his seniority, you can expect formal or ceremonial elements," he said.
Funds will likely come out of the Civil List - money provided by Parliament to meet official royal expenses - the queen's household allowance or drawn from her personal wealth. That is, unless Parliament votes to give the royal couple extra money for the wedding.
Taxpayers at the very least will have to pay for security, which will require a large number of police.
That could be offset by a big boost to the British bottom line. Travel group Visit Britain said the monarchy generated 500 million pounds ($800 million) a year for the economy from overseas tourists, adding "the benefit of a royal wedding year is likely to outstrip that."
Prime Minister David Cameron led lawmakers in the House of Commons on Wednesday in congratulating the couple on their "wonderful news."
"We look forward to the wedding itself with excitement and anticipation," Cameron said.
The biggest fashion decision Middleton faces will be her wedding dress.
Deborah Joseph, editor of Brides Magazine, said Middleton will face substantial pressure to choose an English designer. "It's a British royal wedding, there's no need to look abroad," said Joseph. "She may give a nod to Princess Diana, and use one of her designers, like Bruce Oldfield or Amanda Wakeley, or she may make a statement of her own."
Joseph said Middleton's decision could define bridal wear for the next decade, much as Diana's 1981 outfit became the most-copied wedding dress in history. One easy bet, however: Middleton is likely to use much softer fabric, like tulle or organza, than the stiff taffeta Diana used.
The British media feasted on the announcement. Commentators dredged up memories of the dazzling nuptials of Charles and Diana and newspapers splashed pictures of Kate and William across their front pages. "The New Romantics," said The Times of London, while several papers noted that William had given his betrothed his mother's engagement ring. "With Mummy's ring I thee wed," said The Sun.
Younger brother Prince Harry said he was "delighted that my brother has popped the question!" - and adding that Kate was the sister he had always wanted.
"We're massively excited," William said in a televised interview that marked the first time the couple has spoken publicly about their love affair, which dates eight years back to their days as university students. "We're looking forward to spending the rest of our lives together."
William said he had given Kate his mother's sapphire and diamond engagement ring as a way of making Diana part of his special day. "I thought it was quite nice, because obviously she's not going to be around to share any of the fun and excitement of it all. This was my way of keeping her close," William said.
William, wary of a media he holds partly responsible for his mother's death in a Paris car crash in 1997, said he had taken his time in proposing to give Kate a sense of what life in the royal family was like.
"I wanted to give her a chance to see in and to back out if she needed to before it all got too much," William said. Middleton acknowledged that being in the royal family was "a daunting prospect."
The interview reminded many of a similar TV appearance by Charles and Diana shortly after they became engaged. Diana seemed frightened of the limelight and withdrawn; by contrast, Middleton seemed at ease in front of the cameras. She said she wished she had met Diana. "I would love to have met her. She's an inspirational woman," Middleton said as William looked on.
The future of the royal family depends to no small degree on the success of their union.
Middleton brings youth and glamour to a monarchy tarnished by divorce and scandal. The marriage will link Middleton - a wealthy commoner whose parents, self-made millionaires, founded a successful mail-order party supply business after working in the airline industry - with William, scion of one of the richest families in the world.
A strong, stable marriage - one that lasts decades and produces heirs - could go a long way toward undoing the damage from Charles' and Diana's ugly squabbling and televised confessions of adultery.
"This is their chance to rejuvenate the dynasty," said Patrick Jephson, former private secretary to Diana. "This is an opportunity for a welcome national celebration."