Has the 'Transformers 4' Robot Villain Been Revealed?

Michael Bay has slowly unveiled the cars that will get screen time in the upcoming Transformers 4 movie,

 including two different looks for Bumblebee. But his latest reveal has many speculating about the storyline of the upcoming movie.
Could the 2014 Freightliner Argosy that Bay revealed be Nemesis Prime? His origin story has varied through various retellings of the series, but Nemesis is always a villain and generally regarded as Optimus Prime's evil twin. He could be the product of MECH and the Project: Chimera like he was in Transformers: Prime. Or he could be working with Sideways, who answers to the planet-destroying Unicron in 2002's Transformers: Armada.
We're still not sure which robot will transform from the Argosy, but we do have the basic plot outline for Transformers 4. It takes place four years after the events of Dark Side of the Moon. Scientists and business execs are attempting to harness Cybertronian technology, and things quickly get out of control. Right now, the story sounds like the Avengers plot, where aliens assumed the human race is ready for war when SHIELD starts creating weapons with the Tesseract.
The plot sounds like it's setting earth up for a showdown with Unicron, but would Bay want to introduce his big villain so soon? Considering that the upcoming movie is the starting point for another trilogy, maybe Unicron will merely be teased and left to play the main villain in Transformers 7. What do you think?
Transformers 4 will premiere on June 27, 2014. Mark Wahlberg will star as protagonist Flynn Vincent, who teams up with his daughter Tessa (Nicola Peltz), her boyfriend Shane (Jack Reynor) and his best friend (played by T.J. Mille)r. Kelsey Grammar, portrays Harold Attinger, the film's human bad guy. Stanley Tucci, Li Bingbing, Lucas Black and Sophia Myles will also appear in the film.