I spent a few hours at Washington Square after work. The eyasses were fed by the mother, who then went off to the cross on a nearby church. One eyass explored the ledge going a good way off the nest.
From the webcam, you can see the other eyass has it's leg caught in a plastic bag. There are no signs that the eyass is any danger. Hopefully, as the eyass gets older it will be able to remove the plastic on it's own.
However, there is a slight chance that the bag could get twisted and tighten which would restrict circulation. This would require intervention, so plans are being made to act if necessary.
Update: On Tuesday, 5/8/12, the eyass got free of the bag on its own.