What happened to 3D?

I have 3D in my home theater. I think I've seen every second of fine-arts HDVD content that has been published in 3D. That includes Carmen (Opus Arte),  Lang Lang Live in Vienna (Sony),  Mahler Symphony No. 1 (EMI and EuroArts), Mozart Chamber Music (AIX), and Pina (Wenders movie). My conclusion: there's a small benefit from 3D for everything related to the fine arts, but the benefit generally isn't worth the complications and limitations incurred.

The one exception is ballet. I can watch the Wim Wenders Pina movie in 2D and 3D, and I like the 3D better. But that title was made as a movie by a famous director, and they poured resources into getting the 3D to work with special stages and outdoor shooting. They shot everything really bright so the light loss from the 3D glasses is not a big issue. So if I have 1 guest, we can watch Pina. If I have more than 1 guest, this gets awkward because I only have 2 sets of 3D glasses.

Pina in 3D is a milestone.  But it may not have much real world application to us because almost all our titles come from light-weight camera crews acting far more like reporters than movie directors.

In recent months, no new classical Blu-rays in 3D have been announced. So I think 3D probably is a fad burned out yet again. The industry now seems interested in 4K.  I think 4k probably would be a worthwhile improvement for us. I've been working on a lot of ballet titles recently. Almost all of them would be substantially better in 4k because the ballets need so many full-stage shots. With 1080 horizontal lines of picture, it's hard to clearly resolve the faces of ballet performers in many full-stage shots, especially when the dancers are on the rear of the stage. I'm guessing 4k will probably give the viewer of a film made in a large hall about as much ability to resolve and recognize faces on all performers as the naked eye can give to someone in the live audience. This observation would also apply, of course, to opera and symphony concert recordings. So I would be willing to go through a 4k upgrade if it were backward compatible and able to show our current crop of HDVDs on Blu-ray discs.