My feeling is that the LE model could be the original machine that Stern wanted to release, but it was too expensive, so they cut down the features to the model that was released to market. At the end of the manufacturing cycle, they have limited number of "extra" features - So they ramp up the price accordingly.
If I was an Avatar fan that bought the machine SOLELY becasue of the movie, I'd feel rather pissed off. They should announce an LE run at the same time as the production run, therefore you have a choice.