However, as per yesterday's announcement, we can also expect to see an Avatar land turning up in WDW (probably in about four years, given that construction is due to start in 2013 - sounds like they may be moving the workforce from Fantasyland over to this once it is finished).
Avatar-land is going to be at the Animal Kingdom - presumably in the currently vacant space in the bottom left hand corner of the park - not far from Camp Minnie Mickey.
I'm sure that once upon a time that space had been ear-marked (excuse the pun) for a Beastly Kingdom, or some sort of land themed around mythical creatures. The original logo for the Animal Kingdom featured a dragon in the silhouetted procession of animals along the bottom.
At this stage, for me the jury is out on whether Avatar and Disney can be a successful combination. I will await more news with interest.
(By the way, answers to maths problems postponed awaiting more entries - especially to the "why" part of the question!)