The Avengers are on the cover of the new issue of Empire magazine, and inside Marvel talks about the villains. Superherohype managed to get their hands on the issue, and Marvel specifically says the “Skrulls” aren’t in the movie, but that doesn’t mean there won’t be an army of shapeshifting aliens. More after the quote:
“Who said they were aliens?” he teases. Beings from the Nine Realms, then, ventures Empire? “Closer…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.”
Despite them claiming the Skrulls aren’t in the movie, a couple of months ago some footage from a canned THQ-developed movie-tie-in game leaked out of the Australian studio developing it and it clearly showed Thor and the other Avengers fighting enemies that look like Skrulls. The current rumor is that the aliens in the movie will be called the Chitauri, which is nothing more than the Ultimate universe name for…Skrulls. That will allow Marvel to deny that the Skrulls are the villains, while still have a bunch of green-skilled shapeshifting aliens in the movie.