The official description from the Limited Time Magic site is as follows:
Celebrate the most wonderful time of the year at Magic Kingdom park, where you can enjoy the occasion with an all-new Frozen treat, courtesy of Limited Time Magic! Start the day with the young citizens of Main Street, U.S.A. as they jingle along in their Holly Jolly Trolley show—re-tuned just for the season. Then, as evening enters the scene, put on your Glow with the Show Ears during nightly performances of Wishes and Celebrate the Magic, which includes a special holiday finale and a new sequence inspired by Disney's latest animated feature, Frozen—in theaters November 27, 2013. It's all fun, all festive and all part of Limited Time Magic!