Hi!
This is a good idea, since translations is sometimes a forgotten side of the Project (at least for the Spanish team, don't know about other teams), and this initiative could be interesting for those who want collaborate with translation tasks.
Start translating a module is more or less easy... just set up a translation program, download the PO file and start translating (and reading previous translations to learn about terms, tags, etc). The main obstacle might be the burocracy around a translation team, since there are not standar ways to manage them. In the case of the Spanish team, we have some guidelines about our internal management which might be difficult to understand and follow in a first stage.
So, first of all, I would think about an standar way to manage the workflow of the event (send the translation, review it, comit into git, etc). This would imply to coordinate all team coordinators interested in the event.
About the measure of the success... it's difficult to say, since IMHO quality is better then quantity, so just translating one module, but without errors is better for me than translating 5 modules with typos os grammatical errors. This should be decided by team coordinators/proofreaders.
