The last thing we heard about Attack on Titan's follow-up season wasn't good news. Apparently, development for the show had been put on hold until the manga had reached a certain point. According to sources, the director of the anime's first season, Tetsuro Araki, believed that the manga needed to be four story arcs ahead of the anime adaptation.
Luckily, for fans of the series, there's good news for Attack on Titan. According to the official Twitter account for the show, Attack on Titan Season 2 will air in Spring 2017.
TVアニメ『進撃の巨人』Season 2、ティザーページを開設いたしました!新ページとともに、新キービジュアルも公開しました! #shingeki https://t.co/pKZCLmvlnI pic.twitter.com/AIVZxq0oKt
— アニメ「進撃の巨人」公式アカウント (@anime_shingeki) July 3, 2016
Sure, that's a few months away, but knowing the release window is better than being in the dark!