The news is rapidly making the rounds. Compile Heart (Neptunia and Record of Agarest War developer) announced two games at the Dengeki Kanshasai 2015 today, and one of them is Neptunia VS Sega Hard Girls for the Playstation Vita. There are no other details on the game so far: no release date, no genre, etc.
It’s a crossover that does make sense – now that it’s announced I almost wonder what took so long. A franchise featuring moe anthropomorphizations of consoles meets another franchise featuring anthropomorphizations of Sega hardware. It’s worth noting that this game may be the first opportunity for the Sega hardware girls to be directly playable in a non-mobile title.