Well Ant-Man should introduce Wasp, Wonderman(Vision), & Ultron.
Powerman & Iron Fist are both in the new Ultimate Spider-Man cartoon, so I have no doubt the younger audience has some idea of who they are. Danny Rand(Iron Fist) & Luke Cage(Powerman) are also great rolemodels for Marvel/Disney to bank on, Danny is like Master Splinter, totally zen, and only fights when its the absolute last option, and Luke is a former gangbanger trying to clean up the streets of Harlem. I do not think either could hold a movie on their own, but as a team(which has happened more than any other team up in Marvel) I believe they could. They could also set-up a Heroes For Hire arc, and bring Hulk into the movie.
Doctor Strange is just a favorite of mine, and a very important player in The Avengers(being their only real source for information on all things supernatural). I know Disney has been throwing his name around in an attempt to bring him to the big screen, but nothing has ever been made official.
And, if you think the movie roster of Avengers has depth, then you really have no idea. Hulk, Cap, Thor, Iron Man, Hawkeye, Widow is not an Avengers line-up, as virtually every Marvel hero is at one time or another on the roster, even some villains have been like Venom & Green Goblin(well Iron Patriot, but still Norman Osbourne) have been on the team.
