Well, you can't just add it to the long hauls, because most long-hauls continue on to short-haul destinations (i.e., BOS-PHX-LAX). But that doesn't really matter.
As a passenger, I say yes. It's really long overdue for the airlines to offer TV in flight for all. But in this economy, passenger desires have to stand on their own financial merits.
If AWA could get a good deal on this, and they probably could as the 1st major to do it, then it's worth looking into to see. I suspect it'll be tough to try to quanity the possible revenue effects of such a move, though it obviously works for JBLU.
It would be a big way to pull folks away from the majors, who really aren't in a position to do something like this. But I'm not sure AWA's in a position right now to spend more money on an optional thing like this. That's why they'd really have to study if it would help the bottom line in fairly short order.