Twitch are reporting that Brenton Thwaites and Nicola Peltz have joined the Mark Wahlberg as members of the cast for Transformers 4. Nicola Peltz will play "Marky Marks" daughter in the film whilst Brenton Thwaites will play her boyfriend.
The 23 year old Australian born Brenton Thwaites, is best known for portraying Luke Gallagher in the Fox8 teendrama series SLiDE as well as the Home and Away character Stu Henderson, whilst 17 year old Nicola Peltz is best known for her role as Katara in the The Last Airbender.
Update: In an update on ShootForTheEdit.com, Michael Bay's site admin posted that the story reported by Twitch is false. However, Twitch were the first site to report Mark Wahlberg joining the franchise and S4tE have been wrong in the past. So for now, this story should be treated as a 40/60 chance of being true