Dreamworks has put out a casting call for the two new leads for TF4, plus detailed where the story is going.... so MAJOR SPOILERS ahead.

Story:

Optimus Prime (Peter Cullen) returns with a new group of robot characters, and new male and female leads in "Transformers 4". The story will take off where the last film left off in Chicago, and expand on the history of the first three films in the series.

Starring:

To Be Cast - Female Lead
To Be Cast - Male Lead
Peter Cullen - Optimus Prime
Glenn Morshower - General Morshower

The casting directors are auditioning actors for the new lead roles in the film, as neither Shia LaBeouf or Rosie Huntington-Whiteley are returning. The female lead role is an 18 year old or above who can play high school senior age, and the male lead is an early twenties Texas race car driver who plays the female lead's boyfriend. Shooting will take place in various locations beginning in April or May of 2013. This film is currently being referred to as "Untitled Transformers Sequel".

Executive Producers:
Steven Spielberg
Michael Bay
Mark Vahradian
Brian Goldner

Producers:
Lorenzo Di Bonaventura
Ian Bryce
Don Murphy

Director:
Michael Bay