UPDATE: Warner Bros. has clarified to CBR that the comments made at the end of the Warner Archive Collection panel at WonderCon were with regard to releasing new collections from the original Batman: The Animated Series and its spin-offs, not all-new animated projects.
Outside of the comic book source material, many fans are in agreement that the definitive take on Gotham City's Caped Crusader is the version first introduced in 1992's Batman: The Animated Series. However, while the Timmverse seemingly concluded with Justice League Unlimited in 2006, Warner Bros. Animation may have plans to return to that fan-favorite well in the near-future.
At WonderCon, during the Batman & Mr. Freeze: SubZero panel, Warner Archive podcast host D.W. Ferranti alluded to new projects in the works at WB, noting that they should be of particular interest to fans of Batman: The Animated Series. Unfortunately, he stopped short of providing any further details at that time.
Created by Bruce Timm and Eric Radomski, Batman: The Animated Series originally aired on Fox Kids from September 1992 to September 1995. In 1993, the episode "Robin's Reckoning: Part 1" won a Primetime Emmy for Outstanding Animated Program, and the series as a whole took home a Daytime Emmy that same year for Outstanding Writing in an Animated Program. The show quickly spawned a number of interconnected spinoffs, a theatrical film (Batman: Mask of the Phantasm) and two direct-to-video feature films (Batman & Mr. Freeze: SubZero and Batman and Harley Quinn).
The 20th-Anniversary Edition of Batman & Mr. Freeze: SubZero arrives on Blu-ray March 27.