So I decided to draft a comparable list of Japanese studio closures since 2007...
Developers
-AM Plus R&D (Sega) closed due to Yu Suzuki's retirement, staff reallocated to AM2 R&D
-Clover Studio (Capcom) closed due to restructuring, remaining staff reallocated to internal R&D
-Flagship (Capcom) closed due to restructuring, staff reallocated to internal R&D
Publishers
-Nihon Telenet (IPs sold to Sunsoft)
-Seta
-T&E Soft
...maybe focusing on DS/PSP/Wii is the way to go?