Spoiler Level: Astro- nomically High
...Or, I could be completely, totally and utterly wrong. Amy could just be a more traditional companion who doesn't get to be fleshed out as much as all the other new companions simply because her family's already dead when we meet her, so she just doesn't have anything to come back to except Rory.
Wow, talk about seeing things that weren't there. I really missed the mark on that one!
Once again, the Moff makes time travel an integral part of the story. Heck, not just the story, but this entire season and the next one. So everything with the crack, everything with this whole season, has been him cleaning up the after-effects of something that hadn't happened yet, and no one, the Doctor included, knows who did it or why! That's awesome.
Even more awesome is Amy and Rory staying on for another season as the first married couple in the TARDIS. And wow, did Rory ever prove himself worthy by standing watch over Amy for 2000 years.
Oh, and as to the story title, I'm going with "The Pandorica Opens," because the Pandorica is a crucial part of both episodes, but the Big Bang is specifically referring to the Big Bang II from this episode.
A great wrap-up to a great season. Looking forward to next season, and arguing over what to call it!