multilinguality in Newscoop means that you can have all (or part of) content translated into other language(s). You don't need to create new publication (publications, in the end, must have different urls - site aliases).
You can do this: in list of issues, you will see option to translate issue - that means you're making version of the issue in different language. It will have same url, same number, just the language parameter will be different.
Then you can translate individual articles, or create articles specific for the newly introduced language. Either way, you will be asked to specify the section where you want to put articles. If translating existing articles, you will be prompted to also create translation of the section.
-- Ljuba Rankovic Senior Front End Developer, Sourcefabric ljuba.rankovic@sourcefabric.org