Will the wedding be a small soiree, or a fete fit for a king? And will the bride wear white?
Sarkozy, 52, and Bruni, 40, have kept largely silent on their plans and have not revealed a date. Clues about their style have come from a few comments by Sarkozy, and from their brief but highly publicized courtship in locations from Disneyland Paris to the ruins of Petra, Jordan. The tabloids even showed the couple at an Egyptian beach resort, Bruni clad in a tiny black bikini, Sarkozy in trunks, gold chain and Ray-Bans.
Asked about wedding plans at a news conference Tuesday, Sarkozy said France probably will find out about the ceremony after it happens. However they do it, it will be big news, the first time a modern French leader marries in office.
Star-watchers say anything is possible.
"Initially we imagined a royal celebration like Prince Rainier (of Monaco) and Grace Kelly had" in 1956, said Loic Sellin, editor of the popular magazine Voici. "Now we're imagining something discreet. Although, actually, who knows? ... He's capable of throwing a wedding at Versailles and inviting his friends."
Ordinary French couples must tie the knot at the local mayor's office - regardless of whether they also have a religious ceremony with an official marriage notice published 10 days beforehand. Celebrities are not required to publish the notice in advance, and it's possible that Sarkozy, as president, could get special treatment to ensure his privacy.
Some factors would seem to invite restraint. The marriage would be Sarkozy's third, and he was divorced less than three months ago from his second wife, Cecilia. Cecilia, a dark-haired, blue-eyed former model with a strong resemblance to Bruni, has fanned gossip with reported comments calling Sarkozy a ladies' man, "cheap" and "ridiculous," according to excerpts from a soon-to be released book by journalist Anna Bitton.
The wedding would be the first for Bruni, an Italian-born heiress to a tire company who had a major modeling career and the love life to go with it. Bruni, now a singer, dated rockers Mick Jagger and Eric Clapton, tycoon Donald Trump and actor Vincent Perez. She has a young son, Aurelien, from a relationship with philosophy professor Raphael Enthoven.
With Bruni marrying for the first time, "I think she might need a white dress," said Colombe Pringle, editor of Point de Vue magazine, who said she has called Bruni to congratulate her.
Sarkozy, who has two weddings behind him, can wear an old suit, Pringle joked.
Le Journal du Dimanche reported that the wedding might be planned for Feb. 8 or 9 - and if that's the case, it would be less than three months after the couple reportedly first met.
A speedy wedding would mark the end of headaches for protocol planners in foreign countries Sarkozy plans to visit - though he might still be a bachelor when he goes to Saudi Arabia and India later this month.
The sooner they marry, the sooner the presidency's dignity will be restored, said Dominique Moisi of the French Institute of International Relations.
"As long as the possibility of the wedding is in front of him, there will be rumors, there will be media attention," Moisi said. "The moment he marries her, she becomes the first lady of France, and that's it."
By ANGELA DOLAND