When we were there, it started at that time but then went all day until 6:00 I think. We'd heard that you should line up at least 30 minutes before they open but we only did that the first time we went because we too thought 10:30 was a one-time showing. We actually let our girls do it 3 times during our trip since the princesses are their favorite part of the whole Disney experience. We never had to wait more than 30-40 minutes and the workers encouraged us to have one parent wait in line while the kids went down and made a craft, listened to a princess tell a story, or attend the coronation where they were so excited they got to dance to Belle. It worked out great. They rotate princesses out every 15 minutes or so, so you never know who you're going to get once you get to the front of the line. We had reservations for Ariel's Grotto but cancelled it after they got such great interaction with a variety of princesses at PFF. (We also saw Cinderella and her crew at the entrance to DL one day and they spent some time chatting with the girls so that really made their day.)