The Fairy Godmother, along with Cinderella, Prince Charming, Mickey, Minnie, Donald and Goofy; magically lights the castle every night in a 10 minute show. It's one of the coolest things Disney World does for the holidays, in my opinion.
Yes, the castle is really pretty by itself:
It's so gorgeous. Another of my favorite parts was when the castle lights back up after Wishes, and showing a kid the window where Cinderella lives.
Making magic, it's what I did.