I like being able to watch movies or TV shows on the plane. I don't keep that stuff on my phone and I don't own a tablet. I guess I can hope it'll lower the cost of the ticket, but that's not going to happen. :)
Many flights now have free streaming content from on-board servers via the WiFi. It's basically equivalent to what you'd get from the old screens but you can use your own device to get at it. No need to keep large movies/shows around on your device at all.