And there's always some Negative Nancys that will stand on the rooftops and shout about the death of 3D whenever someone's profits drops by three dollars. As you said, Andy, these are most likely people who have either never seen 3D, or at least have never seen good 3D.. felt they got tricked into seeing The Last Airbender in 3D and have sworn off the feature ever since.
I think what's probably happening is that the general public is starting to be a bit more picky about it, choosing only titles that actually make use of 3D rather than seeing or buying the 3D version for no other reason than it's in 3D. 3D is no longer a sales point in and of itself. It has to be put on something that the audience will say "Man, that looks awesome, I wanna see that one in 3D!!" (for me, the latest example would be Pacific Rim).
I don't blame anyone but ESPN for the failure of this channel. I don't have cable in any event, so I could never have watched it, but by all accounts, it was niche sports on a niche channel. They likely intentionally buried it to prevent themselves from being forced by their customers into shooting ALL of their sports titles in 3D, which would be quite expensive to change over to. Had they broadcasted the major sports leagues (NFL, NBA, MLB) in 3D, on their normal channels, the adoption would probably have been a hell of a lot higher.
The technology is almost there. This is going to happen eventually, no matter what.
Welcome to Rivendell, Mister Anderson.