Re: Characters you'd like to see in future Avengers movies?
If Dr. Strange is introduced in the MCU, I think he'll show up in an Avenger movie. The general audience would be confused as to why this awesome, powerful sorcerer isn't joining the team. Plus, Marvel would use the modern comics as to why he'd be on the team.
Though, I don't think it'd last for long. I can see Marvel trying to do a Defenders spin-off in the future.
"Okay...This looks bad."