Just a brief update - on IRC #wikinews today, we agreed to leave some more time to explore additional options, so that voters are not limited to just saying "yes/no" to the CC-BY-SA. The poll is currently scheduled to begin on September 6, 20:00 UTC.
Please spread news about this poll on your local Wikinews language edition, and help to translate. (FWIW, I think the technical setup of the poll is quite neat, even though the transclusion leads to caching issues -- perhaps templates can be used instead next time, where the using pages are automatically purged on changes.)
Erik