Nice catch, but a slight clarification is needed - PlayOnline is actually owned and operated by SE, not Sony (they originally developed it as the network/portal for all their planned online games, starting with FFXI). It didn't work as well as they'd hoped though and nowadays is only used to access FFXI. But that is definitely a POL reference.
Another SE reference - the Deepeyes enemy in Coerthas Western Highlands is obviously a reference to the name of Gray's military unit in the FF film FF The Spirits Within.
More film and book title references:
The main story quest 'A Series of Unfortunate Events' is obviously taken from the novel and film of the same name.
The name of the FATE in Western Coerthas 'The Polar Express' is again clearly taken from the title of the children's book and film.
A more obscure reference is the name of the achievement 'Lucky Number 7' (for completing the 'Divine Intervention' main scenario quest) - this is possibly a play on the title of the film Lucky Number Slevin.