According to Latino Review, the villains THE AVENGERS will be facing in the Joss Whedon scripted/directed Marvel team-up film will be THOR’s big bad Loki and the Skrulls.
There’s some plausibity to this claim; back in 2009 Marvel Entertainment honcho Kevin Feige told the site:
“In my opinion, The Skrulls are really the only viable threat that would require so many super heroes to fight as a team. Sure, you could have The Hulk as a villain in the beginning, but then they have to come together for an even bigger threat. Something hinted about in IM2, Thor and Cap by Nick Fury’s presence.
Plus Fox doesn’t have the rights to The Skrulls, only the Super Skrull. But this is just my inner geek thinking out loud and hoping.”
Un-named sources claim that Loki (Tom Hiddleston), Thor’s evil “brother” is the main villain, and he uses the Cosmic Cube, which will be seen in CAPTAIN AMERICA: THE FIRST AVENGER and THOR to summon the alien Skrulls to Earth.
Of course, we’re all leery of “unidentifed insiders”, so treat this as rumor. However, other pevious news stories have given this particular item some weight.