Avatarland: A new land currently being built after the hit movie Avatar and specifically the mythical land Pandora which is seen in the movie.
Beastly Kingdom: A planned land for Animal Kingdom that would have been if it had not been cut because of the budget.
Obviously there is nothing anyone (except Walt himself) can do to stop construction of Avatarland, and with all of the planned (not confirmed) projects in Disney's future little will probably be done with the concept of Beastly Kingdom but, I would like to spend some time explaining the good and the bad with each land, and find a victor (in my mind) between the two.
Beastly Kingdom Pros: You don't have to have seen one certain movie to understand this kingdom, dragons and other mythical creatures can already be found in signs, benches, fountains, and more in Animal Kingdom, fits with all audiences, would make Animal Kingdom a full day park, and it has many possible attractions (Click here to see some).
Cons: High budget, would be controversial as to whether or not it will fit into Animal Kingdom (seeing as the animals are mythic), currently not planned, would have to be built far into the future.
Avatarland Pros: Should bring in plenty of money for Disney, will help bring more people into Animal Kingdom and make it a "full day park", will defiantly help get some new E-Ticket rides into Animal Kingdom, will not lead to another "Harry Potter" mistake, and has many possible attractions.
Cons: It is a PG-13 movie which may end up confusing younger kids seeing as they may not have seen the movie, costs alot of money to make, controversial as to whether or not it fits in Animal Kingdom, will be a hit or miss with Disney fans (Such as Dinoland U.S.A. is), seeing as it is based after a movie that is currently creating sequels could cause for a harder job with imagineers.
All in all I think that at the current time Avatarland is the better of the two lands but, in the long run it would definitely be a smart idea on Disney's part to add a few mythical creatures in what could possibly be a mini land.
If you have an idea for a land comment down below! Personally I like the idea of Bookland!