After one of the big shocks in The Avengers, which caused gasps in the audience all four times I’ve seen the movie, theories are running rampant about the future of Agent Coulson. Prior to the release of the movie there were rumors of the final credits scene (instead of Shawarma) being Coulson transformed into the android Vision by Tony Stark, as Whedon has said in the past that if they did The Vision in The Avengers movie he would be created by Stark and S.H.I.E.L.D. as opposed to Ultron.
Obviously that rumor didn’t pan out, but there are bits supporting a Vision connection within the movie itself. At three points in the movie it’s mentioned that Coulson is dating a cellist. At the beginning when he and Pepper are leaving Tony, she asks him about the cellist who he said has moved to Portland, then when Tony arrives at the Helicarrier he offers to fly Coulson to Portland to see her, and then after Coulson encounters Loki; Stark mentions he was seeing a cellist.
What does a cellist have to do with him becoming The Vision? Because the Scarlet Witch is a cellist. And in the comics the Scarlet Witch and The Vision are an item. Marvel Studios is allowed to use the Scarlet Witch in their movies (and Quicksilver) as long as they don’t mention that they’re the children of Magneto.
While both Ant Man and Wasp are almost a lock for The Avengers 2, I wouldn’t be surprised to see them try to work in a couple of other characters; and bringing Coulson back as The Vision would be pretty cool.