Exclusive: Prince William's Wedding: What to Expect

As Us Weekly pointed out last week, the timing of Prince William's 2011 wedding to Kate Middleton is interesting.

"2011 would be Diana's 50th birthday and also the 30th anniversary of her wedding to his father," Katie Nicholl -- author of William and Harry: Behind the Palace Walls and royal correspondent for the Mail on Sunday -- told Us. "This will be William’s way to make sure his mother’s memory won’t be forgotten on the most important day of his life."

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Hailed as the "wedding of the century," the late Princess Diana famously wed Prince Charles on July 29, 1981.

But Prince William's ceremony won’t be at St. Paul's Cathedral, where his parents' televised I do’s attracted more than 750 million viewers.

"That’s been ruled out by William himself," a royal aide tells Us.

(Short-listed spots: Westminster Abbey and St. George’s Chapel at Windsor Castle.)

It still will be equally lavish.

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An insider confirms Britain’s Royal Mint is already designing a commemorative coin for the occasion, and June and July dates are being considered (a palace insider denies a report that July 23 is the date set in stone).

A Clarence House insider told Us the prince has also "made it clear that Kate wants her family to be involved."

But the Middletons "are bound to various secrecy agreements."

She’ll get to choose her bridesmaids -- "definitely her sister, Pippa, Nicholl told Us -- but she likely won't have a say in other details.

Said Nicholl, "It will be her job to look fabulous and be the perfect royal bride."

She'll definitely consider her favorite label, Brazilian brand Issa, though she “might be pressured to select a British designer," Nicholl told Us.

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And in keeping with tradition, London hairdresser to the royals Michael Van Clarke tells Us, she will likely be loaned a tiara from the queen.