Hi, the list is created on the Wikimedia CH server . I announced it on lists wikifr-l@, WMFR technical list (tech at lists.wikimedia.fr) and wikis-territoriaux at lists.infini.fr, I completed the page given by Nemo, and I announce it on wikitech-l@.
Regarding to a regional MW groups I discussed with some people interested by MW in France, and the first action we thought was some discussion space (hence this discussion list); perhaps there will be some other action like a meeting of French MW-interested people, and perhaps there will be a more formal group, but nothing is fixed for now.
@Nemo: in France, there are a lot of local/city wikis , and their community managers frequently have technical questions (e.g. regarding the spam or config); I think some enterprise wiki managers could be interested also by such a list. We will see if the list survives.