4k blu-ray will not work on a standard blu-ray player. For a system that'supported main selling feature is 4k but can't play 4k blu-rays seems about as ridiculous as a phone not including a 3.5mm headphone jack...which is yet another reason to hate Apple now.
I've been saying it for a while... the 3.5mm headphone jack is holding back some features most companies want to do. It's not exactly reasonable for everyone to adopt bluetooth headsets/earbuds/headphones (They can be acquired pretty cheap though, I got a nice pair of headphones for about $20.), but it is something manufacturers have been wanting to get rid of for a while now and I'm glad they are starting.
A standard Blu Ray player can't play ps4 games either.
Just saying the optical drives in todays game consoles are far from standard.
I don't think it's far fetched to believe Sony could patch in support. For all we know the hardware could already be adequate, only held back by drivers that were not finished in time for the launch announcement.
PS3 had several Blu Ray features patched in after the fact (3D Blu Ray) which many thought would not be possible with the existing hardware. 3D Blu Ray is especially impressive because it requires twice the processing and data bandwidth as normal Blu Ray.
PS4 couldn't even play standard Blu Rays at launch until they released the app several weeks later.
