The exceedingly teasing tease uses a simple, grave score to sell that The Avengers will be appropriately huge and loaded with gravitas.  The actual footage includes Thor and Captain America sharing a teamwork moment, the Chrysler Building struck by lightning, Tony Stark looking very concerned about something, some Hulking out, and, of course, a shot of Natasha Romanoff/Black Widow that does not hesitate to sexualize. 

Most interestingly, though, it's capped off by a couple of shots that offer our first look at the bad guys called down by Loki.  Unfortunately they go by really quick and don't rally give an idea of where these flying alien things are coming from.  Basically, they look sort of like Transformers reigning fireballs on the streets of Manhattan.

The tease was revealed as part of today's Avengers Twitter-thon by writer-director Joss Whedon and stars Tom Hiddleston, Samuel L. Jackson, and Clark Gregg.  Nothing too huge was revealed.  Jackson mentioned that the film won't provide back story for the mysterious Nick Fury, while Hiddleston offered insights about Loki's motivation and his relationship with Thor.  Whedon easily dismissed the rumor that Spider-Man might make a cameo in the film, despite the film rights to the webhead belonging exclusively to Sony Pictures.  For the most part, Whedon remained cheeky, as is his Whedonesque style.

In addition to the aforementioned actors, The Avengers stars Robert Downey Jr., Chris Hemsworth, Mark Ruffalo, Chris Evans, Jeremy Renner, Scarlett Johansson, and Cobie Smulders.  Snag some Rogue 3D Eyewear in time to see the film in three dimensions when it hit theaters on May 4th.