I am so on the fence.
On the one hand, the people who object to Avatar land because they don't like the movie annoy the heck out of me. Animal Kingdom needs something like this. It's not what I would have chosen, but the expansion addresses some of the needs of the park. That's a good thing.
On the other hand, these are just pretty paintings. We all know the finished project won't look like this. Budgets are likely to be cut. It doesn't open until 2017. It's pretty hard to get excited about what likely amounts to 2 rides (neither one a true E-ticket) opening 4 years from now. Factor in a divisive IP with a questionable fit to the park and I get why people are underwhelmed.
Personally, I'm cool with Avland. Cameron's presence suggests to me that Disney can't gut it completely. I think it will be a good addition to the park - a park that desperately needs more attractions and a night time show.
What I fight upsetting is the possibility that we might not get anything major between the Mine Train and Avland. That would be a travesty. If Disney can get some Star Wars or Pixar stuff in Hollywood Studios between now and 2017, I'll be a reasonably happy camper. But if we have to go three years between major additions, Avland will be too little too late much like the New Fantasyland.
Is that being unreasonable? I don't think so. I really don't think we're being hard to please at all. I don't think Disney is trying very hard to please us.