During an episode of Jimmy Kimmel Live, Amy Adams revealed that she has recently read the script for the sequel to Man of Steel, and that she will begin her work on the project rather soon.
Unfortunately, she is unable to speak directly about Batman vs. Superman/Man of Steel 2 plot details.
The tentatively titled Batman vs. Superman movie should commence filming in Michigan in February 2014, and the movie should be available for public consumption by July of 2015, just in time to potentially be considered a summer blockbuster.
Source: Man of Steel Fanpage