My hope for this season and for the special was that we would get to see the doctors clone/daughter again, there is only one more episode so that probably wont happen. The only important characters you might expect to still show up are the timelords, but there was a rogue time machine on the loose. Prisoner zero said "Silence will fall" but unless the atraxi are involved in the alliance and the destruction of the tardis it seems unlikely.
The best interpretation I can come up with is that the romans create the myth of pandora / amy pond and her box/jar is the pandorica. One myth recalls that the box is closed too late but that hope is trapped inside which the doctor represents. and that the box was closed too late. and it is later attributed to the greeks or deliberately design to give the impression.
It simply be symbolic of amy's character, a girl with no parents
This episode also gives possible context to the moment in "flesh and stone" when the doctor appears to amy wearing a jacket after leaving the area not wearing a jacket, asking her to remember what he said. This could suggest that their first meeting was for some reason wiped from existence and that was the only point that the doctor could cross his own timeline to get her to remember him.
"If something can be remembered it can come back"
This is not the first time that roman and greek legends were recalled, the doctor hunts the Graphais in van gogh episode with a mirror recalling peresus hunting medusa, the beast in the starship uk is atlas