The "one more thing" at NIS America's press event turned out to be a major localization acquisition from Kadokawa Games - Rodea the Sky Soldier, the action game developed originally for the Wii by Yuji Naka's Prope studio, and confirmed for 3DS a few years ago. Rodea will release in Japan in April, and a North American / European release is confirmed for Fall 2015.
Amazingly, the game will release on 3DS, Wii U... and the Wii. How, we don't know at this point.
The official trailer from NIS America is below, showing similarities to Nights and third person shooting sequences.
2/19: Japanese release corrected