Hulk - Summer 2008 Ant-Man - Unknown Iron Man 2 - April 30, 2010 Thor - June 4, 2010 The First Avenger: Captain America - May 6, 2011 The Avengers - July 2011
Well, there's the schedule for Avengers-related movies that are in the pipeline. I put Ant-Man in there in the hopes that Marvel will get that out in 2009.
CT and I have often debated the best way to do a Captain America movie --- how much time do you spend in WWII before you move him to present day? This might provide a clue . . . you do your Cap movie entirely in the 1940s, probably laying the groundwork regarding a threat (the Skrulls working with the Nazis?) that will return in present day. End on a cliffhanger, with Captain America lost in the Atlantic.
Two months later (or sixty-five years later), the Avengers assemble, Sam Jackson thaws out Captain America, and all's right with the world.