Tom Hiddleston made a speech in character as Loki to announce the new Avengers movie at Comic-Con 2013.
Borys Kit with The Hollywood Reporter stated that after the reveal of 'Thor: The Dark World' and 'Captain America: The Winter Soldier', as well as a look at 'Guardians of the Galaxy', director Joss Whedon took the stage and said, “I have one more thing to add.”
Whedon began by introducing a video with bits of dialogue from the Avengers as the picture began to reveal a metal surface that could have been Captain America's shield or Iron Man's helmet. However, when the camera pulled back the metal surface was actually the head of marvel signature villian Ultron.
The crowd went wild at the reveal of the sequel and the anticipation grows for more information on 'The Avengers: Age of Ultron.'