The countdown is on for Prince William and Kate Middleton’s highly anticipated royal wedding. The invitations have been mailed out for the Friday, April 29 event, and Royal correspondent and William and Harry: Behind the Palace Walls author Katie Nicholl reveals a few wedding secrets for ET!"[Kate is exercising] a bit of control over her wedding day," Katie tells our own Nancy O'Dell. "[It's] very romantic, and being able to surprise not just William but the rest of the world."Of course, everybody is talking about the wedding dress and who the designer will be. (ETonline.com)