The next logical question would seem to be whether 3D will remain confined to the realm of benign spectacle. The world may be on the verge of accepting that 3D can be a legitimate tool to spruce up family flicks and action blockbusters -- like other kinds of fancy special effects, it can effectively give them an extra "wow." (Certainly the wow was what Cameron was after.) But is 3D good for anything else? What did Avatar prove, exactly?
There are actually two separate questions here. One is whether 3D can be used in movies that aren't supposed to be "fun." Arguably, for example, 3D could have been used to bring some additional visceral power to, say, Letters from Iwo Jima. But would that have worked? In theory, dignity would demand that one refrain from startling the audience with 3D blood splatters and the like. Still, would rendering a dead-serious war movie in 3D be callous and tacky?
A preliminary answer to this question may be forthcoming. We learn (via /Film) that Eric Brevig (Journey to the Center of the Earth, Yogi Bear) is planning to make a 3D Korean War epic, to be shot in Korea next year. He says he was inspired by Tae Guk Gi: The Brotherhood of War, which was a stone-faced, sentimental Korean war film (with "Korean" modifying both "war" and "film"). Though not generally a detractor of the format, I've retained a prejudice against wearing plastic glasses to a movie like that. I'm open to Brevig changing my mind, but can't deny the dissonance.
The second question is whether there's any use to employing 3D in a movie without dazzling effects and action set pieces -- "serious" or not. You may recall Cameron threatening to make his next project a low-key drama, filmed in digital 3D. He wanted to prove it could work -- that 3D could be an all-purpose storytelling tool. Can it? With Cameron or without him, I get the sense we may soon find out.