The answer, essentially, is no. Marvel head Kevin Feige recently corroborated as much when he said the inevitable "Captain America" sequel (yes, they are moving forward), "will continue to explore the modern world in another film of his own." And then we saw photos of Chris Evans in Times Square with Samuel Jackson which basically solidifed the fact that "The First Avenger" does end, or contain some scenes in our modern era. So going back to the 1940s is just not gonna happen as much as some of us would like ideally would like (well, provided the first film is actually good).
"Well, we start [shooting] 'The Avengers' on Monday and 'The Avengers' is modern world. Even in the first 'Cap' movie they bring him into the modern world, so that's established," Chris Evans recently said in a mildly spoiler-ish interview with MTV this week.
So "The Avengers" shoots on Monday. What happens in that picture? Well, the plot is largely unknown so far, but the recent 'Avengers' casting additions and confirmations of "Thor" actors Tom Hiddleston and Stellan Skarsgård, does strongly suggest that Loki (Thor's mischievous evil brother) will be one of the pictures' central antagonists as has been rumored for several months now.
Most people have assumed that a younger Chris Evans and a cocky Robert Downey Jr. as "Iron Man"/Tony Stark would butt heads in the film and Evans also certifies that will pretty much be the dynamic. "He's a fish out of water. He's a man not of his time, coming to terms with how the world is now," Evans said of Steve Rodgers/Captain America who is somehow sent from the 1940s to our modern times in the first film.
"There's a dichotomy, a kind of friction between myself and Tony Stark," he said of the 'Avengers' leadership struggle. "They're polar opposites, one guy is flash, spotlight and smooth and the other guy is selfless and in the shadows and kinda quiet and they're opposites and they have to get along. So we explore that [dynamic] and it's pretty fun."
Robert Downey Jr. vs. Chris Evans? Probably no contest, right? Still, should be interesting to watch. "The Avengers" doesn't hit theaters until May 4, 2012, but "Captain America: The First Avenger" is less than three months away and arrives on July 22.