A separated category for different language maybe helpful when someone wants to get some knowledge in their language or ask for help.
And I think we definitely need translation for how-to.
I also thinking about that (for french community), but I prefer waiting the v1.0 to write “how to” in french, when Discourse will be more stable. Focus on english during the “beta”.
BTW, I don’t know what is the best. Use this meta and make it multi-language or create a discourse-fr.org in french only (like other community vbulletin, phpbb, etc…).