The souvenir mugs and T-shirts are already on eBay. The bookies favour a July date, and one punter has bet £1000 ($2075) on a Kenyan honeymoon.
Britain has another royal wedding to look forward to and, amid a wave of officially sanctioned euphoria, the nation has already developed a severe case of "Wills and Kate" mania.
The widely anticipated announcement of the betrothal of Prince William and Kate Middleton yesterday fired the starting pistol on a race to provide everything necessary for suitably flag-waving nuptials - from millions of commemorative tea towels to an appropriately British dress for the bride.
While republicans called for the House of Windsor to foot the bill in a time of austerity, and former palace insiders predicted a new generation of lasting royal marriages, the first signs of an estimated £500 million wedding windfall came within hours of the official bulletin being released - naturally - onto Twitter and Facebook.
Memorabilia were instantly available on eBay £7.95 for a "Kate and William 2011" mug, while one souvenir producer said it had started manufacturing pre-prepared designs straight after the announcement, in anticipation of a 40 per cent increase in trade.
John Wallis, sales director of Aynsley China, which expects its first "royal" bone china to hit the shops by the new year, said: "We'll be making items to commemorate both the engagement and the wedding. Royal weddings are always very popular with collectors all over the world."
Bookmaker William Hill is taking dozens of bets from gamblers willing to take odds ranging from 1-12 on Prince Harry being the best man, to 10,000-1 on the potential future Queen Catherine arriving for her big day sporting Elizabeth Duke jewellery and heading with the second in line to the throne to a honeymoon in Magaluf in Majorca.
A spokesman said: "It is a brisk market."
To what extent this reflected what Prime Minister David Cameron characterised as "a great day for our country" remained unclear, but there was at least no doubting the sense of excitement that swept the highest offices of the land.
Cameron said : "It is incredibly exciting news, and I'm sure that the whole country will want to pass their very best wishes to the happy couple, and wish them an incredibly long and happy life together."
The Queen and Middleton's parents likewise offered their warmest wishes to the pair - who are both 28 and became engaged last month during a holiday in Kenya.
Middleton, whose patient wait for a proposal and decision to work for her family firm rather than pursue an independent career had earned her the sobriquet "Waity Katy", will be the first non-aristocrat to marry an heir-presumptive since Anne Hyde secretly wed the future James II in 1659.
But while the daughter of Michael and Carole Middleton, a former British Airways dispatcher and stewardess respectively, cannot claim aristocratic lineage, she is safely from the higher echelons of British society.
The success of her parents' Berkshire-based business selling toys and party supplies has made them millionaires.