fuku-shuu:

The news was just announced at the Chuugakkou Reading & Live event to its attendees!

This is the Japanese anime season starting in April 2017.

Sources: here, here, here, here, here, here, here…it goes on and on, haha. 

Isayama even wrote a letter read aloud at the event acknowledging that it has been a long time – but he hopes that the fandom still looks forward to it! A key visual featuring the Shiganshina Trio and the Armored/Colossal Titans was also shown to attendees!

ETA: And here is the first main visual as shown at the event!