I have just checked Ken Levine's twitter account and I found some interesting things. Apparently, info on the upcoming DLC is incoming, including a new trailer and, most importantly, a release date -- for Episode 1, that is. According to Ken, the first episode will be dark. He didn't specify, however, if it's just the atmosphere, or the story as well. I'm guessing both. Also, Ken Levine has started the writing process of the second episode, as early as September 18th.
"I think you're gonna like who shows up in #burialatsea #noiaintelling" - September 25
"Soon I can talk #burialatsea part 1 release date. My work on it is long done. Heads down on part 2. BACKWARDS SPOILER ALERT: krad s'ti" - September 25