According to Ken Levine’s response to a fan on Twitter, BioShock: Infinite Burial at Sea Episode 2 will be about 6 hours long — approximately double the time it took to complete the first. This is good news, as one of the major complaints that met the release of Episode 1 was about its scanty length.
While the Twitter user requested the “estimated length of the DLC for a completionist,” it’s not a stretch to assume that casual players will be able to squeeze 4-5 hours out of the DLC. Unfortunately, no release information was announced. However, Levine has been answering Twitter questions left and right recently, including one regarding the release date, to which he replied “you will know soon.”