Joss Whedon had appeared on Hall H at the end of the Marvel Studios panel to showcase a quick video trailer for The Avengers: Age of Ultron. Everybody who was not part of the Comic-Con 2013 hoped and prayed for the teaser trailer to leak online. And now, that's exactly what has happened.
Though the trailer of The Avengers: Age of Ultron has not released officially, the teaser has hit the You Tube. The teaser might not interest you much as all you get to see are bits and pieces of dialogue from the first Avengers film. You also get to see some heavy machines getting constructed and in the end the machinery is revealed to be the head of Ultron. There are images of the Avengers shown in his eyes.
The Avengers: Age of Ultron is due to release on May 1, 2015 and stars starring Robert Downey, Jr., Chris Evans, Mark Ruffalo, Chris Hemsworth, Scarlett Johansson, Cobie Smulders, Jeremy Renner, Samuel L. Jackson and James Spader, with Aaron Taylor-Johnson and Elizabeth Olsen . It is only in the end that we get to look at his face/mask in the final few seconds of the video.