I've been thinking about this for quite sometime. I wonder if someone has thought about this but here's what it is.
Remember the time when Orochimaru carried out his destruction of the leaf campaign? His job was to assassinate his own teacher, the third hokage. His ultimate weapon: resurrection of the previous hokages. The third hokage however as we know, managed to reduce it at least a little so that the third coffin would not rise up and reveal.............Minato.
Here's my confusion: Can a soul which has been doomed to do battle in the deathgod's belly forever be summoned into a reincarnated body? If it cannot be done, then a strange possibility arises: Minato's soul is not in the Deathgod after all. If this turns out to be true, then who was the sacrifice in order for the Kyuubi to be sealed inside Naruto? Does this point towards a possible father-son reunion again inside the good ol' belly?
Before Minato vanished, he did mention that he was leaving and that he was low on chakra. This has to confirm that at least part of Minato's soul is inside Naruto. However the questions above can also lead to a different possibility. So what do you people think?