NIER: Five months later, but yeah.
I found out about Nier by reading news on the Sword Machine blog, and quickly picked interest on it, so I rushed to the official website and several others to find out more information. Here's the main data from the official website:
NIER™
Developer: Cavia, INC.
Publisher: Square Enix, Ltd.
Platforms: Playstation 3, Xbox 360
Genre: Action-Adventure
Release Date: 2010
Nothing is as it seems in Square Enix's latest action adventure game, set in a crumbled world plagued by disease and dark, unrecognizable creatures. Players assume the role of the unyielding protagonist, NIER, resolute in his quest to discover a cure for his daughter, who is infected with the Black Scrawl Virus. With powerful allies and a mysterious book, NIER encounters things that will confound even the mightiest of the warriorsThere are, however, some differences between the 360 and the Playstation 3 titles;
First and foremost, each console will have its own game: The 360 will have NieR: Gestalt, while the PS3, NieR: Replicant. Thus far, the versions are only confirmed for for Japan.
Replicant's version will have a smaller version of the protagonist Nier, and his quest will be to save his sister instead of his daughter. This is the only change confirmed between the consoles: The weapons, skills, scenarios and enemies will remain the same.
Odd, though. I had the feeling that Sony always targeted to higher audiences than Microsoft. Nevertheless, Japanese gamers' response to the character's age was unfavorable, so a smaller version of the guy was created for the PS.
My personal (and obvious) guess is that it'll be similar to Kingdom Hearts, a hack n' slash game with swords, some magic and combos; with a more-adult world and, judging myself by the amount of blood and personal history of the He/She partner of the hero, more adult themes. Oh and, you can find the debut trailer for the game on YouTube.