Italian website BadTaste have revealed that they had a chance to see the teaser trailer and posted the following description. The "announcement teaser" as director Michael Bay recent called it is expected to be attached to either The Chronicles of Narnia: The Voyage of the Dawn Treader or TRON: Legacy.

Transformers: Dark of the Moon, from the teaser, plays it on conspiracy theories related to the moon landing. The first part of the movie alternates images of the control room at NASA and of the astronauts on the moon. The landing is what we know well, as are the famous words about the “giant leap for mankind.” But we did not know what is the journey of the astronauts on the dark side of the moon, until the control room do not tell them that “…then we are not alone.” Then we see some Transformers: the camera comes close to the eye of one of them, which starts to flash. But the camera does not stop, and takes us inside the robot and its mechanisms, making us understand that it’s coming back into action.
Starring Shia LaBeouf, Rosie Huntington-Whiteley, Josh Duhamel, Tyrese Gibson, Kevin Dunn, Julie White, Frances McDormand, John Malkovich, Ken Jeong, Patrick Dempsey, Alan Tudyk and John Turturro,
Transformers: Dark of the Moon opens in 3D, 2D and IMAX 3D on July 1, 2011.