According to Portuguese site Omelete, Michael Bay sat down for an interview with their reporters, and provided some plot points and showed a little footage from Transformers: Age of Extinction. To follow is an overview, according to Omelete.
Stanley Tucci plays an unscrupulous, millionaire designer, who has been building transformers from alien technology. He compares his work to an art form and the original bots to scrap, but when set in the middle of the action, he screams and runs.
Cade Yeager (Mark Wahlberg) enters the movie, carrying what appears to be a piece of a transformer. He’s a widower living with his teenage daughter (Nicola Peltz). The daughter is secretly dating a race car driver, Jack Reynor. There is an accident, and Yeager is suddenly under scrutiny from both the government and also from "alien bounty hunters," something Bay did not explain any further. When asked about the ties between mercenary bots and Decepticons, Bay also declined to go into further detail.
Then there is a glimpse of a different sort of action for the movie, antigravity. The bounty hunters come to Cade’s farm with the intention to abduct his daughter via a gravitational attraction, and lock her up. There’s also a scene that was reportedly shown to the Omelete reporters, in which an ocean liner levitates out of the water and through an intersection, in front of cars.
There’s also a strong indication that Bumblebee’s new “owner” may be Cade Yeager, as there is scene in which Yeager refers to the bot as ‘Bee and tries to calm him down. While we are fairly sure of the presence of the Dinobots in the film, there was no mention of them in this interview.
Apart from the above info from the Omelete, KPopStarz has some fascinating speculation that we will not only see the Dinobots in the commercial spot during the Super Bowl, but also that we may see a glimpse of Unicron, who is rumored to be appearing in the movie as well. There is talk of leaked audio in which a weak-voiced Optimus Prime bids fairwell to Cade Yeager and the autobots, so this may hint that he is seriously damaged, if not killed, in the film.
Producer Lorenzo di Bonaventura, in an interview with Beijing News, revealed not only the total redesign of Optimus Prime and Bumblebee as we knoq, but also some news of the Dinobots:
I cannot disclose the specifics, but you can be sure that the joining of the Dinobots will give the audience new excitement. In addition to Optimus Prime, Bumblebee, the appearance of these classic roles changed, today the world's coolest, most exciting cars will appear in the film, including China's vehicles, whether you are a car enthusiast, you will feast your eyes and be shocked by them.
With as little confirmed info as there is out there right now, surely some of these speculations will turn out true and some may not.
Because these are not confirmed plot points, they can be taken with more than a little suspicion, but at least maybe we are starting to see some bits and pieces of what Age of Extinction may shape up to be.