That would be awesome. The protocol could follow ISO639-1 code for language(with optional ISO3166-1 following it for specific geographic context) just like most places define languages.

ISO639-1 = language codes
ISO3166-1 = country codes

Just the ability to set

"preferred_languages" : ["pt-BR","en-US","en"]

in the posting profile JSON as well as putting an optional

"languages": ["en","es","pt-BR"]

could allow not only PeakD but other Hive interfaces to make their own more personalized feeds.