I bought a cheap dual screen dvd thing off amazon. I hang it from the seats, on on first row and one on second and the kids can do whatever the freak they want back there and it doesn't bug me. I can listen to my stuff and they can do their thing back there. We bought cheap mp3 players for the kids, or ipods and they can listen to their own music too.
At first I was super disappointed with the entertainment options in the expedition, I felt it was inferior to the jeep I was getting out of but now I actually feel like I like this setup better. I ended up going with the base xlt and spending a couple hundred on the dvd thing and some headphones and the kids seem happier than what we had in the jeep.