ScreenRant has posted a possible synopsis for The Avengers which they claim is from a call sheet which mentions the Skrulls and Kree. This could open the door for Kree heroes like Ms. Marvel and Captain Marvel to make their way onto the screen. The sheet also confirms that Lou will be playing the voice of The Hulk.
"A superhero team called “The Avengers” do battle against two separate alien extraterrestrial humanoid life forms. The Avengers are a superhero team, consisting of a group of Marvel Comics heroes aka “Earth’s Mightiest Heroes”. The aliens that The Avengers will fight are called “The Kree” and “Skrulls”. These two extraterrestrial races become embroiled in a war for ages that ultimately makes its way to Earth, and the Avengers unite to intervene with all their power and might combined."