7 Spoileriffic Things You May Want to Know About The Avengers | GeekDad | Wired.com: 7. The reveal in the post-end-credits scene is of the new villain, presumably for Iron Man 3.
Who is it? Thanos!
Thanos!?! WTF?!?
Thanos is an Avengers-level threat, not an Iron Man-level villian.
I thought for sure, since they were filming Iron Man 3 in China, that the villian would have to be The Mandarin.
Maybe they're introducing him here in order to build him up for Avengers 2.