I'd like to propose an unlikely but theoretically possible scenario for this Green Goblin rumor:
What if all the Lizard stuff was a misdirection? Some directors - most recently that I remember, Michael Bay - have talked about how they need to keep the internet guessing by misinformation campaigns and such.
Again, I don't believe it, but might be worth batting around - at least until Comic Con when, you would think, Sony will make an official announcement.