Looks like J.J. Abrams snuck an interactive "trailer" for Super 8 inside the Portal 2 video game that was just released.
Judging from the official trailer, you appear to be inside the train that carries the alien right when it gets in the accident.
A video of a extra map in Portal 2, called "e1912". People suspected this could be related to the ARG, when clearly it is something else entirely.
To load this map and experience the short interactive trailer for yourself, type "map e1912" in your console at the main menu and press enter. The map will then load. Or go to the Extras section and click Super 8, the map will then load for you.
Set in 1979 Ohio, the film will follow a group of six young children as they use a Super 8 camera to make their own home movie. One night while filming near a remote stretch of railroad track, the children witness a truck collide with an oncoming train leading to a catastrophic derailment. Amidst the fire and destruction, something emerges from within the wreckage, something inhuman.
Super 8, due out next summer, is directed by J.J. Abrams, produced by Steven Spielberg and stars Kyle Chandler, Amanda Michalka, Elle Fanning and Zach Mills.