TemporaryTourist.com is reporting that beginning July 23rd Disney will begin testing a new procedure for the standby line at the Anna and Elsa side of Princess Fairytale Hall. The popularity of the Frozen princesses has resulted in standby lines between 3 and 5 hours.
Per the report, the new procedure will be to fill the existing standby line upon park opening. Once the standby line is filled, guests will be directed to Magic Kingdom Park Support, located on the other side of Prince Charming's Regal Carrousel. Magic Kingdom Support will issue guests a 30 minute return window on a first come, first serve basis. This will be a return time for the standby line and the the time frame will be strictly enforced. It is expected that this will keep the standby wait times at approximately 30 minutes.
The new procedure is expected to run from July 23rd through July 25th. According to the article, disabled guests using the DAS card will follow the same procedure for the standby return time, except they will enter the Fastpass+ queue instead of the standby queue.
The article also reports that during this time an identical system will be tested at Soarin' and another attraction (speculated to be Test Track or Toy Story Mania). A similar process is currently taking place at The Legend of Captain Jack Sparrow attraction.