[UPDATE: Michael Bay Says reports of this casting are completely false.]
New flesh-and-blood players are coming aboard for Michael Bay's Transformers 4 (not the official title), for reasons of allowing the sci-fi franchise to move forward in a different direction without being rebooted. Similarly, there are going to some new robot characters appearing in the film, for reasons of Hasbro heads wanting to make more money on merchandise and toys.
At first, initial reports pegged the TF4 human leads as a high school girl and her car-racing boyfriend. That suggests this could be the rare Bay-directed film with a female protagonist; however, those characters are perhaps too close for comfort to Megan Fox and Shia LaBeouf's in the first couple Transformers movies - and thus, indicate the fourth chapter won't be as 'serious' as promised.
Things have changed a bit since then, as Interwebz rumors about Mark Wahlberg signing on for TF4 (being fresh off shooting Pain & Gain with Bay) inspired its director and screenwriter Ehren Kruger (Transformers: Dark of the Moon) to bring the actor onboard - and make any script changes accordingly, to accommodate having the big-name star occupy an important role. Hence, Wahlberg is now one of the leads in the film, playing the father to the aforementioned young woman (with casting for the latter role ongoing for the past month or so).
Twitch is reporting that the roles of Wahlberg's daughter and her boyfriend have been landed by candidates previously-shortlisted for the respective parts - namely, Nicola Peltz (The Last Airbender) and Brenton Thwaites (Home and Away).
UPDATE: Bay himself is denying this rumor, going so far as to post on his personal Website: "Actor announcement on some web sites last night about Transformer cast joining Mark are completely false." Obviously, for now, the money is on this being strictly a RUMOR.
Peltz and Thwaites are essentially newcomers - as far as the average Transformer fan is concerned - given the obscure nature of Thwaites' television work here in the States; not to mention, Last Airbender didn't exactly give Peltz an opportunity to shine. As it were, both have started to make a name for themselves, with Peltz appearing in the buzzed-about Bates Motel TV series and Thwaites showing up in Disney's Maleficent movie starring Angelina Jolie.
That's to say: the pair are in pretty much an identical position as Fox and LaBeouf before they starred in the first Transformers. Whether or not Peltz and Thwaites' characters will mark an improvement on Mikaela and Sam - or feel like uninspired variations - remains to be seen.
In case you missed it, Bay previously offered the following about the story for TF4:
“The movie is going to continue 4 years on from the attack on Chicago which was in the last movie. So it’s going still to have the same lineage but going in a full, new, different direction and it actually feels really natural how it is going in that direction.”
Transformers 4 (still awaiting the official subtitle) will hit theaters June 29th, 2014.