In a break with tradition, reports CBS News Correspondent Elizabeth Palmer, Kate will travel to the site of the wedding, Westminster Abbey, not in a carriage, but in a car.
Williams and Kate will travel separately to the Abbey, but will travel in a carriage together after the wedding to Buckingham Palace in a festive procession that will include several of London's major landmarks.
At the ceremony, royals watcher and Majesty magazine Editor in Chief Ingrid Seward told CBS News, "The most terrifying moment of all will be when she has to walk down the aisle. But she will be on her dad's arm … and then Prince William, hopefully! - will be waiting for her at the altar."
On "The Early Show" Wednesday, longtime royals watcher Victoria Arbiter told co-anchor Erica Hill about some surprising aspects of the announcements:
The route from the wedding -- through Parliament Square, Whitehall, Horse Guards Parade and the Mall, is likely to be thronged with well-wishers anxious for a glimpse of the couple, who are expected to make a brief appearance on the palace balcony once they arrive.
Next will come a Buckingham Palace reception hosted by Queen Elizabeth II, William's grandmother.
Officials said the guest list will be drawn from the wedding congregation and will include representatives from the couple's official and private lives.
Prince Charles' office announced that he will host a dinner and dance for his son William and his new bride that night at Buckingham Palace. The couple's close friends and family will be invited, Charles' office said.
The official wedding update also specified that the wedding ceremony will begin at 11 a.m. Middleton will arrive by car, officials said.
The palace said the Dean of Westminster will conduct the service and the Bishop of London will give the address.
Charles' representatives said further details will be announced as the wedding date nears.
There has been much speculation about Middleton's choice of a designer for her wedding gown, and about the guest list and entertainment choices, but no firm details have emerged.