That was too light of a word. It's technical achievements are incredible, and it has some strong accolades, but I have always seen it more as a phenomen than something that merits a sequel.
In my opinion it was a beautiful, but okay movie. I bet people say the same thing about Tree of Life though, one of my favorite movies though.
I also sometimes wonder if this will ever happen especially the more it is put off. I wonder how many people actually have an Avatar sequel on their radar as being something they really look forward to.