According to Latino Review Marvel has re-hired Captain America: The First Avenger screenwriters Stephen McFeely and Christopher Markus to get started on the script for a sequel.
Chris Evans revealed recently that he signed a 6 movie deal with Marvel (3 Captain America movies and 3 for The Avengers) so it was only a matter of time before the company got to work on the Captain America sequel.
Assuming Steve Rogers doesn’t get transported back to the 1940s during The Avengers his next solo movie would likely take place in modern times and follow on from the events of the team movie. It’s still to early to tell which direction they could go with the sequel as we haven’t seen the first one yet, and The Avengers won’t be released until 2012.
Captain America: The First Avenger will be released July 22nd and also stars Hugo Weaving as Red Skull, Hayley Atwell as Peggy Carter, Sebastian Stan as Bucky, Samuel L. Jackson as Nicky Fury and Tommy Lee Jones as General Chester Phillips.