Autobots: Springer, Grimlock, Ultra Magnus and the Aerialbots.
Decepticons: Overlord, Straxus, Snare, Hydra, Buster and the Stunticons.

 

Blaster. Since I can pretty much cross out the chance of Jazz ever returning, Blaster is the next best bot because he almost has the same personality. I'd see him as a white 2012
dodge charger with blacked out headlights, taillights and windows. Oh and ya can't forget the sweet sound system !!!   !!!

 

This guy:

 

Rollbar:

Springer:

And Cyclonus as a Cybertronian jet, and Scourge as a Cybertronian spacecraft.

 

SoundBlaster:

Autobot Blaster:

 

Cyclonus:

Galvatron:

 

Decepticons
Shockwave: Only surviving officer from Operation Pillar.
Thunderwing: Surprisingly caring for a Con leader but tends to get obsessive on missions and needs Shockwave to stop him from wasting resources and troops.
Soundblaster: No relation to Soundwave except fro being his replacement. Is similar to G1 Soundwave.
Buzzsaw: Works with Soundblaster and is quite similar to Laserbeak.
Strika: Female Decepticon version of Ironhide.
Thundercracker: A fun Con who likes nothing better than a long and intense dogfight.
Onslaught: Decepticon bruiser who's twice the size of Optimus and can take and give a quite a big beating.

Autobots:
Optimus Prime: Reflecting on recent events.
Grimlock: Optimus' savage second in command. A lover of Earths violent nature and has taken on the form of a robotic dinosaur as they are no longer hiding from humanity.
Ratchet: The same as ever.
Bumblebee: Has randomly lost his Rambo abilities.
Sideswipe: Same as ever.

Maximals
Primal: quite similar to OP. After OP refused to step down from command after his decisions as leader were brought to question, Primal declared war on Optimus and his followers. Cybertronian and human alike. He regrets it but will no longer tolerate Optimus.
Mirage: Sided withe the Maximals as he's always preferred Cybertron to Earth.
Wreckers: Decided they do not like Optimus' decisions.
Blaster: Rival to Soundblaster.
Divebomb:Rival to Buzzsaw.

 

Lets be honest, the only new things we`ll get are Decepticons and maybe one Autobot (Who will probably be a companion charecter to the new human main charecter)

The Autobot companion is likely to be young, inexperienced and comedic - think along the lines of a mix between Bumblebee, Cliffjumper, Hot Rod, Hot Shot that sort of stuff.

New Decepticons will likely be one or two fan faves mixed in with others. Tidal Wave is a charecter Bay has always shown an interest in (Shown in Tf1 and Tf2 concept art) Probably 3-4 new Decepticons who featured in the comics along with their leader (Who may just be Meg`s again) along with the rest of the Decepticons (being Drones)

New Decepticons;
Tidal Wave
Thundercracker and/or Skywarp
Rumble (Continuing the tradition of a cassette bot appearing in each film - Frenzy, Ravage, Laserbeak - Rumble, Ratbat, Buzzsaw)

 

That's what I'm predicting. I also expect Tidal Wave shall trip over a fish and blow up.

 

YES!!!!!!!!!!!!!!!!!!!!!!!!! but lets have him as like a "radio personality" person, instead of the smooth criminal like jazz was.

 

No new Autobots. Please lol. They need a smaller autobot cast so they can develop the already existing autobots.

 

The only new character I want is Bulkhead. But even so, I'm not gonna get my hopes up too much like the last two movies. If anything, I'll be happy if Soundwave and Shockwave somehow return.

Agreed. Hopefully they'll just focus more on Sideswipe and Dino instead.

 

Hot Rod
Ultra Magnus (who is actually Galvatron in disguise)

 

So long as the number four is not in the word transformers in the title I will probably see this.

 

Hoping for Blitzwing and Cyclonus on the con side, and for Bots Trailbreaker-but as an SUV-like vehicle and not a truck to help differenciate him from Ironhide.

 

Bruticus and the Combaticons. Hell, a five-man mercenary team out for Decepticon revenge that turns into a huge fucking monster could be the entire villain force of the next movie.

 

That truck is fucking awesome

 

I want a small group so we can have some characterization

Alright, here's my full cast:
Autobots
Optimus Prime
Ultra Magnus
Bumblebee
Trailbreaker
Smokescreen
Hot Rod
Kup

Decepticons
Megatron
Starscream
Soundwave
Shockwave
Blitzwing
Scourge
Cyclonus

 

I'm surprised no one said lugnut

 

I think they should add Evac from the TF ride in TF4.