I do not think I have seen this theory. What if the Tardis shrapnel that we saw was from the tardis of the doctor whom River Song might kill during the events of the pandoricon? Maybe that causes the explosion?
My theory of what will occur is this: I think we are witnessing an alternate universe play out. There are many clues to this theory being right. In this episode the doctor flat out says that a new timeline will be created. In the episode with the dream world there is a play on what is real and what is not. And during the episode with the angels we see another doctor. What if the "real doctor" is trying to direct Amy Pond to sealing the cracks of the alt universe so that it can heal and close up?