Jessica Lange was recently interviewed about the upcoming third season of American Horror Story, and she revealed that it will be about witches and witchcraft, but she doesn't know anything else about it.

Jessica Lange promotes American Horror Story
When asked about Season 3 of AHS, she replies, "They've just sent me the first two scripts... we've set it in New Orleans. It's about witches - it's about witchcraft. Other than that I honestly don't know much more about it."
When asked about working with the likes of Kathy Bates, Lily Rabe, Sarah Paulson, and Patti LuPone, all of who are new addition to the S3 cast of AHS, Lange replies, "It certainly is an interesting group of actors - again."

Jessica Lange on American Horror Story
Lange is currently campaigning for television awards season, which is almost upon us. Till date, Lange was actually nominated for both seasons of American Horror Story in most awards ceremonies for lead actress. No doubt, she will get nominated once again, but the real question is - does she have a good chance at winning? Considering that Claire Danes is almost a lock again this year, it's unlikely. However, if she continues this way, getting nominated several times and not winning, then there's a very high probability of her winning in another few seasons or so.
Jessica Lange interview about American Horror Story