A New York Times article on 'cage-free eggs' that my good friend tipped me off to; she grew up on a farm and her mom still raises chickens and sheep back in Minnesota.
Again, a reminder that if you really want to go sustainable/ethical, it's best to not only check the label but know the source. And that's where local is better, for some things at least.
For me, free-range eggs are much better just from a taste standpoint. And obviously ethically they are better as well. It just might not be possible for large producers to supply truly free-range chickens -- because for one thing, that would require more land for them to range on. Multiple, small producers that supply local consumers with truly free-range eggs might be the most sustainable option.