We're given sources in Skyrim that say they are different, but previous sources said they are one of the same.. then the Imperial studying the Skaal interprets the Skaal's All-Maker to perhaps be Alduin, while apparently it is actually Akatosh. So... what gives? Are they 2 different things or are they 2-sides of the same time coin?

I think Alduin is a mirror-brother of Akatosh who was split away during some Dragonbreak and the whole Skyrim main plot deals with the Dragonborn weakening Alduin enough so that old Aka gets the chance to http://www.youtube.com/watch?v=SMWi7CLoZ2Q the soul of his little brother and make himself whole again.

G:\Anu\Aka\Alduin.DVH