Just got back from 5 days at DL. On two days in a row, we saw Aurora in her pink dress when she was in front of the castle for signatures. On on the next day, she was back in blue. On our last day we ate at Goofy's Kitchen and she was wearing pink as she went around the tables for pictures and autographs. I didn't think to ask if there was some kind of a schedule to this, but I'd be curious to find out.
Also, for the first time, we saw several princesses together. One day, Snow White and two other princesses were together over by the wishing well, but we didn't get there in time for pictures. But another day, just as we were finishing a visit with Ariel, Snow White and Belle came over and we got a picture with them all 3 together.