Here's some of the information already released about the game:
http://www.playstationlifestyle.net/2015/06/17/nier-ps4-is-not-a-sequel-says-director/
"A new NieR game being developed by Square Enix and Platinum Games was revealed during E3 2015, and some new details about the upcoming title have since been revealed.
In an interview with Famitsu, Director Yoko Taro revealed that the new NieR game will not be a sequel, but did mention that the “setting is connected” with the previous NieR.
The setting is connected, but that doesn’t mean the story is connected. This game is set in the future, so it’s okay if you start with this game. Rather, people who played the previous game and come into this thinking it’s a sequel might be confused.
He went on to say that “some characters will appear” from the previous title, “but not as core characters.” It was also revealed that development on the game is only 10 percent complete at this time, meaning NieR has a long way to go before getting released.
In a separate interview, Taro revealed that NieR will feature three playable characters, although not all of those characters have been revealed yet. Two of the characters can bee seen in the NieR trailer from E3 — a small boy and a while haired girl."
http://uk.ign.com/articles/2015/06/19/12-things-we-learned-about-the-new-nier
"This week at E3, game director Taro Yoko and executive producer Yosuke Saito revealed more details about the new Nier project. Though they were reluctant to go into detail about the combat system and story, they were willing to share a few other juicy tidbits about the game. Here are twelve things things we learned.
There are three main protagonists in the game: the girl in the trailer (who is a completely new character), a young boy, and a character not yet revealed.
The story takes place in the same world, but most locations are new. Even if areas from the original Nier appear in the game, they will be completely redesigned.
The theme of the game is "agaku," a Japanese word that means to struggle/desperately fight your way out of a situation. (According to the translator.)
The story is completely new, and has very little connection to the original Nier.
Characters from the previous game may make a brief cameo, but will not be a part of the main story.
The development team is toying with the idea of allowing players to experience multiple playthroughs using each of the main characters.
The reason Platinum Games was chosen to develop the game was because of the developer's ability to do fast-paced combat.
The three protagonists may travel together at times, but not always. (This is still being decided.)
The reason the game is on the PS4 is because of the platform's high specs.
One of Platinum Games' goals is to have the game run at 60 FPS.
The early version of the battle system's is described as very "Nier-like."
There will be more towns and cities in the game, which will have a dilapidated look and feel to them."
Maybe some information on the new locations, characters and the story of the game could be revealed.
It's possible PG could release an in-engine teaser of something, but that may be way too soon considering the game was only 10% into development at E3.
Maybe PG are a few percent further along and can give some new details about what's planned for the game.
https://en.wikipedia.org/wiki/Nier_New_Project
Apparently production began in 2014, the last Nier released in April 2010 and that began development after Drakengard 2 in June 2010.
