They are in fact a trio of excellent RPG developers. Thus, what better way for them to unite than to create an RPG called Trinity Universe - as has been announced today.
The game is a 3D dungeon crawler RPG and features two plot lines: Goddess and Devil King. Gust worked on the scenario for Goddess, while Nippon Ichi did the Devil King scenario. Idea Factory will be pulling the whole thing together.
The game is currently known to be a Playstation 3 exclusive and will launch in Japan sometime this Autumn.