There have been a number of companies, including Disney, that have done free roaming animatronics. The biggest problem is they are simply not durable and dependable enough to deal with the rigors of being on stage for 8-16 hours per day. They are seriously awesome when they work, but they are as dependable as a $2 Rolex.One thing I am curious about with this project is the use of AAs. I know that Cameron, some time ago, commented on the 64 axes-of-motion for the Na'vi faces alone and that the AAs in this expansion will be game-changing.
Beyond the Na'vi, I am wondering about the animals that inhabit Pandora. Does anyone remember when someone posted a video that showed free-walking animal designed AAs. A guy was walking one and it was walking beside him with such life-like motions it was stunning. At one point he kicked it and it lost its balance but managed to steady itself. It was so real looking it was bizarre. That type of tech could be used to full effect in a land like this to really match the walking trails in Africa and Asia. I am really hoping that technology makes its way into Pandora.
Puppeteering is still the best option for a theme park environment.