There was no official announcement made about the release of Telltale Batman until Telltale Games Head of Creative Communications Job Stauffer tweeted the following:

This announcement hints that we’ll get to see a sneak peek of Telltale Batman, and maybe a glimpse of the upcoming The Walking Dead Season 3. It may be possible that we could get a firm release date at E3 as well. 

Telltale has already released many episodic games based on big franchises like Game of Thrones, The Walking Dead and Borderlands. And while this new Batman adventure is just another in that lineup, it will be the first game to use Telltale’s brand new game development engine. Hopefully we’ll get a taste of what improvements that engine has made when E3 rolls around.