I think 4k displays are a great thing. I think 4k (or higher) preservations of of titles is awesome. I think 4k home media is largely a waste. For most titles, DVD is still good. For high detail films, Blu-ray is pretty much all you need. Going higher produces diminishing returns and it won’t help most titles. Most titles aren’t 4k ready. I believe that 4k maxes out what 35mm film can capture. Higher is good for things shot on larger film stock, but those aren’t as common. I don’t think the average person is going to be able to tell the difference between 1080p and 4k. I think the extra display pixels will do more for the content than increasing the resolution of the content.

I know there are many people out there who will have a setup that enables them to really tell the difference, but they are a minority (though I’m not so sure that this site doesn’t lean the other way). 4k is more suited to 3D and gaming than motion pictures.