A particularly interesting post from Roger Ebert, a man, in my opinion, of many interesting posts.
I've enjoyed the 3-D technique from time to time, finding it particularly effective in Avatar, Coraline, and a couple other animated movies, off the top of my head. It can be done well, if incorporated into the original story and vision of the movie, but do the pros outweigh the cons? Is it really worth the extra cost to see something like Green Hornet in an extra dimension, even if that dimension often tends to blur out the other two? Especially odious are films where the technique has obviously been slapped on in haste: for example, Clash of the Titans.
Walter Murch, an incredibly esteemed film editor and sound designer, who worked on some of my favourite movies, notably Apocalypse Now, goes further, and suggests in the above-cited article that the 3-D technique is at odds with science in terms of our visual perception. We have simply not evolved as humans to percieve images in this way, with our eyes focusing at one point and converging on another. It's just weird and difficult, like, to use Murch's example, patting your head and rubbing your stomach at the same time. It can be done, sure, but it's challenging and frustrating.
It's merely one opinion among many, but Murch is certainly an expert in this field, and would have to deeply understand how people watch movies in order to have achieved the level of success he has in his career. So, it's worth some serious consideration. Then again, people have been known to make some scientifically baffling decisions now and then, so the 3-D trend might just rage on.