Yes, of course you can.
Yet, the most urgent should be to build a language pack for v1.4.0preview.
You can translate patch-service_en_US.properties, bpm-messages_en_US.properties, jbpm_en_US.properties, webdav-messages_en_US.properties and workflow-messages_en_US.properties. They are not translated at all because these files are new (except patch-service, but that file is changed on every release).
remaning changed files are :
action-config_en_US.properties
bootstrap-spaces_en_US.properties
lock-service_en_US.properties
permissions-service_en_US.properties
version-service_en_US.properties
webclient_en_US.properties
They are all only slighty modified, except for webclient which is deeply changed.
It should be easier that i translate myself theses remaining files as it's the best way to ensure translations are coherent.
But if you're too fast at translating the first ones, i'll let you translate the others. What tool do you use ?
Laurent.