Thor was coming off tragically seeing his brother "die", finding love on Earth, not being able to return to Earth after devoting himself to Asgard and his father. Iron Man has become the most public superhero since Cap, having two very public battles with Iron Monger and Whiplash. Becoming the center of a Supreme Court hearings on the morality of him owning the rights to his suits. Hulk has been on the run. Trying to stay out of the governments eye. Cap has been awoken from a 70 year long ice nap, after fighting what seemed to be the most deadliest villain of World War 2 in Red Skull. Broken promise to meet his gal for a date. Do you think the film correctly captured each of the main four characters going into the big film. You know by time of filming a solo movie and then the big assemble, writers can make the littlest change and it could effect what you saw from say IM2 and into Avengers.