It couldn't be more official now: Sega is bringing back the Valkyria Chronicles series.
The title has been confirmed, development has been confirmed, and now we have our first teaser trailer hinting at the characters and story. These characters were described with a bit more detail in the
Famitsu article from earlier in the week. It's also been stated by Sega that this game and any that follow it will be known as the "Revolution" series, while parts one through three will be known as the "Chronicles" series. This implies the new game will launch an all-new story.
The new Valkyria game is currently scheduled to be released sometime in 2016, but only Japan has been confirmed to get it so far, though if you're looking for good signs, the "Valkyria: Azure Revolution" title has also been trademarked in the US. In addition, an HD remaster of the first game (I should hope so, it made its debut on an HD system) will be coming to Japanese Playstation 4s soon.