From the UK Independent:

An interactive trailer for J.J. Abrams's super-secret film Super 8 has been included in the PC version of the video game adventure Portal 2, released on April 19.

A "walk-through" of this Super 8 footage is available as a special feature showing the interior of train boxcars in which an alien from Area 51 is apparently being transported.

Abrams, who directed Star Trek and co-produced the television series Lost, has worked with cross-promotional ideas and viral marketing on Lost and the film Cloverfield.

A YouTube video shows the zooms and other features, allowing a peek at details before and after the train crash, as shown in the conventional trailer. Portal 2 gamers can play the role of a passenger on board.

As reported in MTV, this feature could indicate there may be a Super 8 video game.

Starring Elle Fanning (The Curious Case of Benjamin Button) and newcomer Joel Courtney, the story follows small town kids who witness a train crash and discover the terrifying truth behind the so-called accident.

The film, produced by Steven Spielberg, will be released June 10 in North America and rolls out in international markets through July and August.

Here's another link to the trailer with commentary: http://www.youtube.com/watch?v=NgwAmeWhC7c