I am a little disappointed that the annotated edition is tied in with the normal editions of this book on here. This was a Christmas present, a book I long coveted. I wrote two papers on The Wizard of Oz in grad school, one for a witchcraft literature class and one for a class on film adaptations of literature and I found the background information fascinating: for instance, Baum's use of witchcraft imagery was likely influenced by his mother-in-law, a fierce yet oft-forgotten suffragist who compared disenfranchisement of women to the Salem witch trials. It's hardly a coincidence that Baum wrote one of the first children's books with a self-sufficient female character.
The weekend before Christmas, I regaled my boyfriend with all of this trivia as we watched Judy Garland's Dorothy in the land of Oz not knowing that this book was neatly gift-wrapped in his closet at the time -- good job, dude. :)
Though very few of the annotations provide me with new information, personally, I love this edition. Beautiful and interesting, it adds a lot of texture to the story. A must for any fan.