enterprise2004: In the comics, Iron Man, Thor, The Hulk, Ant Man, and the Wasp founded the Avengers after Loki had taken over the Hulk and sent him into a rampage. They didn't find Captain America frozen in ice till issue 3.
Were they formally the Avengers by then? I admit this is going back to the 60's here and I am going on Marvel guides and Wikia's here lol
El_Caz: I wonder if the Red Skull will play any part? He sort of vanishes asgardian style in the Captain America movie. I'm kind of against it, but we'll see.
They have been pretty good at keeping the leaks down so far. I doubt Red Skull will appear now, if he was to re-appear it would be better in Captain America 2 but I'm personally hoping for Baron Zemo.
The Skrulls have been mentioned but the trailer showed nothing of them and it would make little sense for Loki to ally with them. Marvel also had the Infinity Gauntlet on display at some Thor exhibition and it appears very briefly in Odin's vault in the movie. It would make sense if the gauntlet was Loki's aim and that would make a set up for Thanos in Avengers 2.
Edit: Marvel also have an Inhumans movie, a new Fantastic Four re-boot and a Guardians of the Galaxy movie in the works so Thanos is a good bet.