I did this with my DD, several years ago when the princesses were the most important part of our DLR time. First you stand in line, probably for an hour, even if you are one of the first ones there. It will be an hour till you get to the princesses, if you line up early. They did have a few little activities for the kids to do, but those took all of ten minutes. There is no guarantee of which princesses will be there. When we did this, you could meet the princesses, then go to "boutique" where they did hair and face painting. probably, like 50$ but it was a once in life time thing that we would do. After she had her hair done she looked soooo cute that I lined up again to have the pics taken with her adorable hair and the princesses. Memories that we will cherish, and glad I did it then, because the next year she was OVER the princesses and wanted to do rides instead. For a bit, (maybe the last two years), they stopped the Coronation Ceremony where the kids can dance with the princesses, but I remember hearing somewhere that they were going to do this again.
It is a long wait, but you can get three princesses for one wait time and if your child is princess crazy, I think it is something I would take the time to do....