Since the GI Joe team had nearly been reduced to what one could put in a bag, they need more guys. The cast of the first movie is never really declared dead (aside from Duke). Destro is below Germany in hibernation or something. Zartan is dead.
I'd like to see Shipwreck brought in.
Destro could be brought back, and forms the Iron Grenadiers, which eventually become the main protagonist of the film.
The Crimson Twins, perhaps a dual role by someone creepy enough to pull it off.
Edit: I had Shipwreck to be played by Hugh Jackman, then I had this idea. Major Bludd played by Hugh Jackman. It's for the best becuse Bludd's voice needed to drop.