Even though I'd not participate in those sites as I'm no where near fluent in anything but English, I think after a period of time — another [6-8 <s>weeks</s>](http://meta.stackoverflow.com/q/26491/54262) months? — to let Ask Ubuntu establish itself, those could be tried and might be successful.

However, I hesitate to fracture the community.  It's been pointed out here (comments on another answer) and elsewhere (including meta.SO; don't ask me where, but please comment with links), it can be better to have more people communicate, sometimes poorly, in English rather than never get an answer because it's on a separate site.