I think the team should consist of Iron Man, Thor, Captain America, Hawkeye, Hulk, Ant Man, Wasp and Black Widow for the sequel, with maybe Ms. Marvel being set up for a sequel in it.
Villains should be Ultron or Thanos (presuming he's just set up in the first Avengers flick) and Ultron should build Vision to set him up for future films.
Originally Posted by Indy1Jones
How about new avengers Wolverine Spiderman maybe after their films are done.
Sony and FOX own the rights to those characters so Marvel Studios can't use them.