The game will be released in fall 2013.
Marvel has announced that new Lego: Marvel Super Heroes game is under development and will be ready for release in fall 2013. According to the press release, the game will feature over 100 playable characters, including Captain America, Thor, the Hulk, Spider-Man, Deadpool and Wolverine. Also mentioned in the teaser are the Fantastic Four, Guardians of the Galaxy, and the X-Men.
The press release mentions that the plot will involve Nick Fury assembling a team of heroes to face Galactus and Loki. No word on whether the game will lack a voice cast (similar to earlier Lego games) or whether it will follow Lego Batman 2's lead and provide voices for the characters.