I did end up going somewhat early but they didn't do anything early.
They taped David Cook at about 1pm, Air Buddies about 1:45pm and Sarah Brightman about 2:15pm. This year David Cook and Sarah Brightman were both taped at a stage in Town Square. There were several great vantage points up by the stage off to the sides, although there were a lot of bad views because of high shrubs all around and the 'extras' areas were not good views. There were also okay views from the Train Platform. And, they let a few hundred people inside the shrubs to be right up at the stage.
They were both very fun with the crowd and each sang their song about 3 times plus some warm up. Then, they brought out 3 really, really cute puppies and put them on the curb on Main Street surrounded by a lot of people pretending to watch the parade and shot some pictures as if the puppies were watching the parade. It was really cute.
Tomorrow it appears they are doing the cast of Mary Poppins on the Town Square Stage around 8am and then moving the crew down to the castle to tape David Archuleta at 11am. Then, they are taping the parade throughout the day. Miley and her dad are rumored but couldn't get any confirmation.
Anyone know more??