Wow... Such an epic composition!
Across the top, I see Cosmos, Springer, Grimlock, Powerglide, Silverbolt, Blades, Skywarp, Jetfire getting decked by Starscream, Treadbolt, Bruticus, Astrotrain, Shadow Commander Nemesis Prime, Megatron, a second Bruticus, Ratbat, the Nemesis, Acid Storm, Dirge, Dropshot, Heavy Load, Storm Cloud, Thundercracker, Ramjet, Thrust, and Octane. Is there a Bruticus repaint in the Classics/Universe line? Hun-Grrr?
On the hill in the background are Cheetor and Dinobot, I think. Or is the one on the left Jolt?
Along the ridge are Inferno, Red Alert, Hot Shot, Mirage, what looks like a second Inferno, Smokescreen, Bluestreak, Leo Prime, and Roadbuster. One bright red Inferno and one dark red Inferno, perhaps?
In the foreground, we have Bumblebee, City Commander Ultra Magnus, Sideswipe, Powered Commander, Sunstreaker, Rodimus, Prowl, someone who looks vaguely like Jazz, Ratchet, Hound, Optimus Prime, Wheelie, Warpath, Brawn, Beachcomber, Ironhide, Devastator, Ravage, Laserbeak, Frenzy, Rumble, Galvatron, Cyclonus, Onslaught, Overkill, Soundwave, Soundblaster, and Drag Strip. Is that
Shattered Glass Jazz next to Ratchet?
Aside from Starscream, it's not really possible to tell which Seeker is which until they get colors.
I'm guessing Thundercracker is the least prominent one, grouped with Thrust and Dirge (who were also BotCon exclusives) and that Skywarp is the aggressive one on the left.
Not shown are Blaster, Vector Prime, Countdown, and Darkwind. Quite frankly, I'm amazed that so many characters were included!