That's my home park so I feel equipped to Answer this. Love "Avatar" or hate it, the choice is perfect. Animal Kingdom is a suffering park (although surpassed DHS this past year in attendance). Animal Kingdom is all about The Past (Dinosaur), Present (Safari) and the Mythical (Everest Yeti). If you've seen "Avatar" then you would know there are literally dozens of different creatures in the movie, all mythical. Plus the entire theme of "Avatar" is very VERY green. It fits into Animal Kingdom flawlessly. It's a way to attract a different group of people at Disney. It's not for the typical crowd, it's for the hardcore fanboys that would spend a week at Universal but will now buy a ticket to Animal Kingdom to see Avatarland. Plus Disney decided to buy this project before the release of the second and third movies (a bold gamble, but the decision might pay off).
Haven't seen Avatar, so as I said, I can't judge or assess the actual scope of the project in this regard, plus, we haven't seen the actual park yet, but I still don't think it's a great fit, except to compete with Universal, as you mentioned.
How about improve AK, and as several of us mentioned, get rid of the carnival! Add more animals, maybe design some new attractions shows with nature/animals/environmental themes?
What about use some of that money to fix DHS and Innoventions at Epcot?
We absolutely need more parks, as there are too many guests for what is currently there, but fixing current park issues/problems would have been a better idea, and then work on a new park.
I realize that James Cameron puts his all into projects, but I'm still not sure if the giant egos on his end, and I'm sure there are some on Disney's end are going to keep this project from being built in a timely manner. Blue people...really? This is the vision for AK.
Just like with the carnival, I'm not so sure it's a good fit, so I'll have to reserve judgment until I see it. The theme as you mentioned above, really hasn't been pursued that well (really, the Yeti can't be fixed?), so perhaps this is the only way to make that work?
We like AK as well - we actually don't really go on rides. We like to walk around and see animals, a few shows, tree, etc., but it does need some updating and fixing, and I'm not sure that blue people are the answer to that.
Just my .02 cents, Tiger