Originally Posted by The Infernal
I think what they did in Thor in regards to suggesting the Asgardians are merely advanced aliens rather than Gods may be both an advantage and a disadvantage for IM3 and future Marvel movies. I mean after seeing Thor and then the Avengers you could argue it would be easier to do the alien origin of the rings (or at least hint at it) in IM3 and not step out of the world they've set with the first two films all that much.
Although the problem from my point of view is that both IM3, The Avengers and future MCU movies are in a risk of essentially giving the message that there is no magic in the MCU. Which would in turn meaning anything like Dr Strange if it were made into a film could potentially be omitted from being included with the rest or that any villain that does essentially use magic either can no longer use magic or isn't available at all.
Lets not forget there's supposed to be some things in the Asgardian Vault on the DVD/Bluray. We THINK Strange's orb is in the Vault so I wouldn't put it past them to sneak Mandrin's rings somewhere.