I suppose all computer-animated movies will be in 3D from here on in -- there's no reason not to, now that render time is so manageable. Once you've done the geometry, lighting, and motion modeling, you're basically done, and rendering a stereo pair instead of a single image is essentially free. I'm not sure whether it really enhances the experience, though. I don't think it makes a big difference.
I'm intrigued at the way the computer animation industry is sort of loitering on the near brink of the Uncanny Valley. The technology is already capable of much more lifelike human characters, but the designers are staying "cartoony" on purpose, to avoid creeping people out. (Nonhuman characters are exempt; the Uncanny Valley phenomenon is neurologically specific to our perception of human figures, faces, and skin. Computer-animated nonhuman characters are already routinely composited into otherwise live-action science fiction, fantasy, and horror movies.) Brave could have been made in live action, with appropriately composited critter animation. But there were a few "madcap" sequences that might have posed a challenge.
Even though it focuses on two strong female characters and their interaction, I think Brave fails the Bechdel Test because all of the interaction is about the mother's desire for her daughter to conform to societal gender roles -- in other words, whether directly or indirectly, they are always talking about boys.
But I'm quibbling. The story was trite but well-told, the art was pretty good, the characters cute and engaging. At one point it occurred to me that this movie ought to do really, really well in Japan. It has got to appeal to the Anne-of-Green-Gables/Nausicaa/Princess Mononoke esthetic. It was the most kids'-anime-like thing I've seen yet out of American cinema.