As stated earlier in the thread:
1. This omission is surely a launch pain. 3D movie playback will undoubtedly make it's way to the console sometime soon.
2. 3D playback on the One actually has several challenges that the PS3 (and probably to a lesser extent the PS4) won't face. Microsoft has to figure out how to display Snapped apps during 3D playback. And how to deal with users hitting the guide button during 3D playback. The PS3 didn't have to deal with the first and just slapped the XMB overtop everything for the second. The PS4 doesn't have to worry about the first, and I'm not sure how it will deal with the second. And this is ignoring the vast difference in experience with the Blu-ray format (Sony helped develop the technology while Microsoft, to my knowledge, has never shipped a product with a Blu-ray drive)