Of COURSE we're speculating! To me, that's the magic (pun intended) of the Harry Potter series. Not only has JKR sparked an interest in children to read, a lot of (supposedly sensible) adults on this thread and another I'm following are having fun with what to happen to fictional characters.
It's not great literature. But it is a fun read.
Now, something else to consider:
I know we've all read about the great bond between Lily and James, but could it be possible that a tiff will be revealed between them, that Snape found Lily heartbroken and they, um... consoled each other.
Then Lily and James patched thing up, but Harry is REALLY Snape's son? And he's been so awful to him because Harry had to go to Muggles because Snape couldn't claim him?
Hmmmm....
That would be crazy! I do remember from Harry following Snape in the pensieve that Lily came to his defense when James hung him upside down. I am thinking that there is a deeper connection between them....
Not even remotely likely. Except for the eyes, Harry is a dead ringer for James Potter.