I am glad this is finally confirmed (well, semi-confirmed, I guess).
Changes nothing for me and my plans, I'll still use my launch PS4 as I have no intention to upgrade just for graphics.
The games will be playable on my PS4, graphical sacrifices I don't mind, if I managed to enjoy games in 576p and 720p, it's not going to kill me if my current games look worse than 4K.
I mean, I play games right now that look much better on PC, and I couldn't care less if they do. So I really won't care if somebody plays a better looking game - they paid $500 for that, good for them.
And a 4K TV is not in any of my plans any time soon. Once they are 250 like TVs are now, then OK. Until then, who cares, my 40" crappy Grundig is perfectly fine.
As I stated before, unless my PS4 dies, my next console is due around 2021/22 (probably a PS 5.5 by then).