Looks like it's going to be "the Armor Wars" with the Mandarin (who apparently isn't Chinese. I'm not sure how to feel about that) in the mix. Nice to see them going with a classic big name villain (sorry Whiplash) to carry the movie. Hopefully with this being the last Iron Man movie (I hope) they can blow they're wad on classic armored villains like Titanium Man and the Crimson Dynamo. And with AIM and Iron Patriot in it, it's sure to be epic. And that scene of Tony walking through the snowstorm, hauling his armour looks fantastic. I got high hopes for this one.
Also, I wonder if AIM is going to be a big presence in the movie universe after this film. It would make sense and could easily tie into Cap's next film as well as the Ant-Man movie (come on Edgar, finish the awesome movie you're currently working on to make an awesome Marvel movie). After all, AIM is the sister organization to HYDRA but with less Nazis and more science (which I think should be Volkswagen's new slogan).
Also, let's play the "What will Marvel hint at" in the post credits coda.
My theories:
A) Hank Pym!
B) The Winter Soldier
C) Gaurdians of the Galaxy (somehow)
D) If this is the last one, than rather than a next movie coda, it'll be just a really strong scene to cap off the franchise and say "thanks for watching"