I've just finished translating OJS 2.1 language files into Spanish (ES_es). I translated locale.xml and email_templates_data.xml as estated by Kevin in an earlier post
I don't know who I should write to so it can be incorporated as official translation for OJS 2, so it can reach a wider community. I also have a few technical doubts about the information at the beginning of the files.
It can also be an interesting starting point to translate to other "Spanish" languages (ES_ar, ES_mx, etc.).
I hope my (hard) work can be useful for other people using this wonderful system. Waiting for an answer ... best regards,
Sergio Ruiz - http://www.revistaesalud.com