There is also the fact that the new Guardians of the Galaxy Marvel comic book has Iron Man featured right at forefront.
In addition, a new Iron Man 3 space suit was revealed in the form of a toy for the movie.
Update: And Thanos and Drax first appeared in an issue of the Iron Man comic book, #55.
Previously, Kevin Feige was pretty adamant that none of the Avengers would be appearing, and what Downey Jr. has to say fits right with that.
Downey Jr. tells EW the following (bold my own):
The whole Avengers thing [with $1.5 billion in global box office was such a relief and such a confirmation of [Marvel Studios President] Kevin Feige’s vision for this all along. As Kevin has put it, the next step after that is to bring in someone like Shane Black and – without pretending that the Avengers don’t exist – find a way to go back to a kind of re-investigation of Tony’s world, which he thought would be, one, fun for the audience and, two, would rock in a different way than The Avengers. But we can’t help it — everywhere you look now in every Marvel movie there are opportunities where certain new pals of his could be useful. So they’re in the atmosphere, so to speak, but I wouldn’t expect to see them on the ground in this one.
"In the atmosphere" and "won't see them on the ground."
The Avengers 2 assembles May 1, 2015 with Iron Man 3 on May 3, 2013, Thor: The Dark World on November 8, 2013, Captain America: Winter Soldier on April 4, 2014, the Guardians of the Galaxy movie on August 1, 2014 and Ant-Man on November 6, 2015..
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