First up, let's go with the clip, which you watch below or in high definition at Yahoo! Movies.  The short excerpt comes from late in the film, when Loki's army has laid siege to Manhattan, and it has the two stars of last summer's Marvel movies, Chris Evans and Chris Hemsworth, doing battle with the invaders.  Not only that, but it also features a little taste of the über heroic score from Alan Silvestri.

After seeing these two actors play fighting against imaginary bad guys on the Cleveland set last year, it's fun to see them up against actual villains here:

Next up, here's the featurette, entitled "Tension."  Hailing from IGN, this video doesn't include too much new footage, certainly nothing mind-blowing, but it does have interview snippets with Joss Whedon and company talking about how none of these characters should be inhabiting the same movie, really.  And it has at least one great little moment from Tony Stark.  Listen to what he calls Thor and try not to smile.

After the enthusiastic response to the film's first screenings this week, Marvel and Disney are really going nuts with the marketing of what is, in some respects, the biggest superhero movie ever attempted.  Certainly in terms of its ensemble cast, which includes Evans, Hemsworth, Robert Downey Jr., Mark Ruffalo, Jeremy Renner, Scarlett Johansson, Samuel L. Jackson, Tom Hiddleston, Clark Gregg, and Cobie Smulders. 

The waiting, generally believed to be the hardest part, will finally be over when The Avengers hits theaters nationwide on May 4th.