It is obvious that they wanted to expand both the physical park and the number of hours it could serve guests. However, Avatar seems like a strange fit. Africa, Asia, Pandora...wait Pandora isn't a real place. Dino land isn't a real place either, but at least dinosaurs once walked the Earth. I agree with the post that said they should have added South America, or one of the other continents. The boat ride could have been on the
Amazon and they could still have used the Banshee ride as an E ticket, or come up with something else. The could have added a volcano or dozens of other cool things from South America and it would have also been very easy to theme a restaurant or 2.
That is water under the bridge though and they are committed to adding Avatar land at this point. Having been in the park when it is dark, I can say that most of the areas do not offer much after the daylight is gone. Avatar land with its luminescence is likely designed to be as much a night spot as a day one. There also probably won't be as many live animals to disturb in Avatar land which may have factored into the decision.
I didn't watch the movie when is was released, but recently purchased a copy just because I figured it must be good if Disney invested a whole land in it. Others will likely do the same. While a bit weak in story line, the original movie was technologically ground breaking. Now more than 5 years later, I expect the second to be stunning as well.
Do I think Avatar was a great choice? No. Am I excited to see it completed? Yes.