Plans are well underway for the wedding of the century.
As for the wedding party, William's choice for his best man is said to be a no brainer.
"I'd put a lot of money that Prince Harry will be the best man," said royal biographer Andrew Morton.
Kate's younger sister Pippa is reportedly a shoe-in for the position as maid of honor.
Elton John is expected to perform at the wedding. The singer famously gave a moving performance at Princess Diana's funeral in 1997.
As for the guest list, there is one royal who likely won't be invited—the disgraced Duchess of York, Sarah Ferguson.
"Sarah Ferguson is as likely as me to get invited. If Fergie got tickets she might be selling them on eBay!" commented Morton.
INSIDE EDITION also learned that behind the scenes, Kate was extremely jittery when she sat down with William for their first ever joint interview.
Royal correspondent Tom Bradby of Britain's ITV conducted the interview seen round the world.
"She was very nervous. She's never done anything like this before. If it had gone wrong, it would've haunted her for years and years and years," said Bradby.