Originally Posted by cherokeesam
Good guess. I've always suspected Red Skull was actually transported to the same section of the galaxy as Thanos at the end of CATFA, and that Skully would be granted superpowers by Thanos and team up with him at some point.
Thanks. A lot of people have suspected that. Some wishful thinkers even claimed they saw him hanging out with Thanos in The Avengers when they first watched the movie in theaters (which upon later viewings it was confirmed he wasn't). In any case, I'm certainly glad that they have learned not to kill major villains off anymore in the MCU. I hope it stays that way with Mandarin, though I could see Malekith dying.
As for anyone else who Joss could have been thinking about as a second villain, what about Absorbing Man? After all, Loki created him in the first place, he would have added some extra punch to the battle scenes, and the character could have used some redemption after the Nick Nolte fiasco in Ang Lee's Hulk. He's also a villain that could really spice up the MCU rogues gallery (for either Hulk or an Earthbound Thor) in the future.