OK going off the concept vault stuff...
I think the most likely are the ones I highlighted in bold. These will be the new ones at TRU this fall.
They could also add some repacks ala Blowtorch.
- Gung-Ho
- Rock n Roll v2
- Storm Shadow v2
- Barbecue (Team Bravo Firefighter)
- [strike]Beachhead[/strike] 50th
- [strike]Cobra Eel[/strike] 50th
- Cobra Officer
- Cobra Shock Trooper
- [strike]Crimson Guard Immortal[/strike] FSS
- Crimson Shadow Guard
- [strike]Flint[/strike] 50th
- G.I. Joe Police Unit 4
- G.I. Joe Trooper (tan uniform)
- [strike]HEAT Viper[/strike] 50th
- [strike]Hit & Run[/strike] FSS
- [strike]Kwinn the Mercenary[/strike] Retaliation
- [strike]Lady Jaye[/strike] 50th
- Laser-Viper
- Shipwreck
- [strike]Steel Brigade Commander[/strike] convention
- [strike]Steel Brigade Delta (light green uniform, different tooling)[/strike] convention
- Stinger Driver
- Tele-Viper
- [strike]Clutch (Pursuit of Cobra VAMP Driver)[/strike] convention
- Cobra Infantry
- [strike]Data-Viper[/strike] Retaliation
- [strike]Viper Officer[/strike] 50th
- Dreadnok KAOS Crew
- Echo Faction Trooper (Grunt?)
- Heavy Alley-Viper
- HISS Driver (Pursuit of Cobra HISS Driver)
- NOMaD Warrior
- [strike]Pit Training Duke[/strike] ROC was a long time ago
- Raven’s Wing
- Ripcord Arctic Diver I really want those new diver accessories!
- Snow Serpent
- Steel Brigade v.2
- Zartan
- [strike]Beast Ninja
- Dark Ninja Master
- Ghost Ninja Henchman
- Gold Ninja (Actual name not known)[/strike]
- Ninja Warrior Monk
- [strike]Red Ninja Dice[/strike]
- [strike]Snake Ninja Master[/strike]
- Urban Ninja
- [strike]Mutant Zombie
- Toxo-Zombie
- Zombie Cobra Commander
- Zombie Cobra Shock Trooper
- Zombie Cobra Viper
- Zombie Echo Faction Trooper
- Zombie Ninja
- Zombie Steel Brigade[/strike] convention
- [strike]Zombie Storm Shadow
- Zombie Viper[/strike] zombies are more likely a Club convention thing I can't see Hasbro making any more
I think the most likely are the ones I highlighted in bold. These will be the new ones at TRU this fall.
They could also add some repacks ala Blowtorch.

And if you have an extra one kicking around that you would be willing to sell/trade for, let me know!