Here is an excerpt from Feige's intriguing discussion with Empire about Loki's Army in The Avengers:
"Who said they were aliens?"... It's not Skrulls, I've been clear about that. Beyond that, we want to hide it. The identity of the alien race is not impactful. It exists in the comic books, but we're not setting up the Kree-Skrull war or anything like that."
Similarly, Feige touched on the rumors about Red Skull showing up in the film:
"Was [Red] Skull vaporised at the end of ['Captain America: The First Avengers'], or thrust into another realm? That remains to be seen. It would be fun to see Skull in future, but he's not in this one."
So, assuming that Feige isn't just flat-out lying, it doesn't sound like either the Skrulls or Kree are in cahoots with Loki, as has long been speculated; likewise, Red Skull apparently won't be one of the Avengers' main foes either.
All the same, there is still a lingering question: Do Feige's comments also apply to The Avengers' post-credits scene - or could, say, a certain red-skinned baddie still show up briefly, during that portion of the film?
Everything will be revealed at last when The Avengers hits theaters in the U.S. on May 4th, 2012.
Source: Empire Magazine (via Comic Book Movie)