A few weeks back, Nippon Ichi began teasing a couple of 20th anniversary titles. The platform for one of those titles has been revealed in this week's Dengeki PlayStation to be PlayStatin Vita.
Outside of the platform and some art, it appears that the magazine does not provide any details. It doesn't even list the genre.
This Vita title is the 2nd anniversary game that Nippon Ichi was previously teasing. The first title, an RPG with Noizi Ito artwork, is still platform TBA.
This is just an early report based off the usual flying get sources. We'll hopefully get a more detailed report from Dengeki later in the day (assuming there's anything else to report on).