Even though not one frame of film has been shot for The Avengers, a new report claims that Marvel has assembled a secret teaser trailer for the movie, which will likely play before either Thor or Captain America: The First Avenger this summer. And it will feature a secret new villain.
Thor's adopted brother, Loki (Tom Hiddleston), will reportedly be the main villain in The Avengers. It seems that Loki will team up with The Skrulls to square off against The Avengers. We reported in December that The Skrulls and Kree would do battle with the superhero alliance, although this is the first we're hearing about Loki as the main villain.
Loki will apparently use the "cosmic cube" from Captain America: The First Avenger to summon The Skrulls to Earth. None of this has been confirmed at this time.