(Mind, in those circumstances, a choice between being able to stretch out in business class vs. having WiFi in coach would tilt even harder towards the former. But after about 8 hours in the air, I do find a lack of communications really starts to bite.)
For example, there's plenty of RPGs of all flavors and settings that would have you exploring, conversing, and battling. Many don't have high system requirements, either, so could be comfortable to play on a netbook or tablet.
Edit to add another idea: I know some flights have games you can play with people in the seats next to you. Why not a plane-wide chatroom of some sort on a web portal? Then you could textually converse with many people without bothering anyone and without any bandwidth/latency restrictions.
A long-haul flight is so much more pleasant with wifi. There's only so many movies I can watch (for me, 1 or 2) before I get bored out of my mind.
It can get lonely on a plane if you are traveling alone. The people around you aren't always willing or able to talk (they may be asleep, don't speak English, or are preoccupied with a movie), so you may end up sitting for extended periods with nobody to talk to.
Being able to chat to friends while in the air makes the experience more comfortable than any seat ever could.