I'm a little surprised at Cartoon Brew's insistence than Avatar be considered an animated film. I don't know if the reason is because it is the highest grossing film in history and they want animation to have some of the glory or if it's because James Cameron is so insistent that Avatar should not be tainted with the 'A' word. In any case, there are reasons (beyond whatever anyone thinks of Avatar) why I don't think considering it an animated film is a good thing.
Those outside the film business may not be aware of the distinction between production and post-production. In a live action film - one with no animation or special effects - production is the shooting of the film. Post-production is what happens after the film is shot. Those things typically include editing, music, sound effects, dialogue looping, the sound mix and titling.
When a film does include special effects, unless they are done in camera during the regular shoot, they are considered post-production. In the past, certain effects like in-camera matting, hanging miniatures and glass shots were done during production, but most effects were done during post.
In what we would all acknowledge as typical animated films (Snow White, Toy Story), animation is production, not post-production. In films that have animated elements added (Jurassic Park), animation is done in post-production. This may seem like an esoteric distinction, but it's the difference between what is central to a production and what sweetens a production. I am not in any way dismissing the importance of post-production. A film's music score has a huge impact on how the film affects audiences and certainly Jurassic Park's impact depended tremendously on the quality of the dinosaur animation, but in each case, the post-production elements are driven by what has already been shot.
Animators may have worked over Avatar's motion capture and added creatures, but their work was driven by what had been shot (or in this case, recorded). To pretend otherwise is disingenuous. There is no question that Jack Pierce's Frankenstein make-up added to the audience's perception of Boris Karloff as the monster. However, many actors at Universal played the monster (Bela Lugosi, Glen Strange), yet Karloff is generally considered the definitive performance. While Avatar's animators supplied more than digital make-up, it's still the underlying motion captured performance that counts.
I've written extensively on how fragmented the process of making an animated film is and how so many of the acting decisions are made before the animator starts work. The character designs, the storyboard and the voice performance all make acting decisions that constrain the animator's interpretation. There is no question that motion capture is yet another constraint, probably larger than all the others. To insist that Avatar is an animated film is to marginalize animators even more than they are in what are generally considered animated films. Is this the direction we want things to go? Better to agree with James Cameron and focus our attention on films where animators create, not enhance, performances.