Perhaps something the current PS4 is missing or something.

Psst, Sony may be reading this, it could all start here. :P

A feature that you can watch TV and play games at the same time.

Or maybe you can just play Detroit Become Human.

Recording in 1080p 60fps

A seperate disc slot that can read LaserDisc.

More freedom regarding file management/file playback. I have entire TV shows and movies on my PS3 that I ripped from a thumb drive. Gimme more of that. Can't really think of anything else I'd need out of an entertainment device, it's already got Vue for TV and I happen to have a Spotify premium account for my music.m (running this in the background while I play multiplayer sessions is great)

Upload pics to use as background wallpapers.
External HD support.
PS2 physical BC.

Ps vue supporting multiple ps4's simultaneously.

Theatrical release movies available to watch from our console for the price of a movie family ticket.  

Ps4 is a transformer that will do my bidding while not playing games.  

PS Vue on multiple PS4 devices is a must.

PS Vue/Other Apps while gaming (or a direct rip off of snap) would be huge for me.

Ability to have more apps open, or better app management, basically, catch up with Android and iOS.

Refresh the web browser, or allow firefox to build a browser.

Allow me to interface between two PS4's since I would assume with Neo being out a lot of people will have a OG and a Neo.