The PS4 won't support playback of 3D Blu-rays, according to the online user guide (spotted by TheSixthAxis).
Though DVDs and Blu-rays are fully supported and CD support is to be patched in, the "Playing video on disc" section of the User Guide says that 3D Blu-rays are not supported.
The PS3 plays 3D Blu-rays just fine, which makes this especially strange. Sony has left 3D by the wayside in the past two years, having attempted to push it hard in the middle years of PS3's lifespan. This would appear to be another nail in its coffin.
And Mr. Mike's final question is who really cares? Sure I own a 3DTV, have 6 pairs of 3D Glasses (P.S. Came with TV I DID NOT BUY THEM!!), have a Bluray 3D Surround Sound System, and I even sometimes get Bluray 3D versions of movies due to the fact that mostly the movie bundle packs are cheaper than the stand alone disks. But here is the thing I Never watched the Bluray versions, and never going to! Don't care, maybe sometimes when at a movie theater Only when the movie was built for 3D like Avatar was... There Done!