Even given the Sha's origins with the Old Gods, we in Pandaria still know very little of them.
I would like to take this opportunity to add whatever information I can about them to the archives of the Lorewalkers. Of course, that becomes a bit problematic when they're trying to kill us.
That doesn't seem to be a problem for you, though. Could you do me a favor and jot down some notes about what you encounter out there? It could help a great deal towards understanding what we're fighting.