well working for Sony enables them to interact with other Sony studios regarding with improvements and technologies...
imagine,
for example:
naughty dog is working with insomiacs and guerilla...
etc.
PLAYSTATION®2 is the yesterday.....NOW.......still......A_L_I_V_E
Consoles own:
Nintendo: Famicom(japanese NES, Family Computer), GBC, GBA, DS, Wii
Sony: PS1, PS2, PSP, PS3
Microsoft: future 360 owner