This is Nippon Ichi's New Witch
New PS3 title was actually revealed about a month ago.
Dengeki PlayStation has a first report this week on Nippon Ichi's new PS3 RPG, The Witch and the Hundred Cavalrymen. Read all about it here
It turns out that we already heard about this game a little over a month ago. In fact, Nippon Ichi provided a teaser image.
That's an image of the the witch of the game's title. Nippon Ichi CEO Sohei Niikawa shared the artwork at the Akihabara Denkigai Festival event in early August (and Impress Watch grabbed the above pic).
As detailed then (see this story), Niikawa revealed the game to be an action RPG with character designs from Takehito Harada and music from Tenpei Satou. He did not reveal the platform, but did promise a formal announcement towards the end of September... which is where we are now.
From what we're hearing, the character's name is Metallica. We're still not sure if you control her or the hundred knights mentioned in the title.