Fatal Frame 5 twitter campaign got some interesting results...

[Wyrdness]

KylieDog said:

They do not co-own the franchise.  Three Fatal Frame games released on PSN last year. 

http://www.computerandvideogames.com/354688/nintendo-secures-co-ownership-of-fatal-frame-series-report/

http://www.joystiq.com/2012/06/22/report-nintendo-now-co-owns-fatal-frame-ip/

Koei own the rights to the original 3 games that's why they're allowed on PSN as they retain ownership of those 3 while Nintendo owns the rights to every game made in the franchise from 4 onwards this is why the Remake of two as well as 4 can't get ported as the partnership gives Nintendo the rights of future installments, it's like Sega and Bayonetta, Sega has to give the green light on things despite it being PG's franchise.