Addressing various points:
1. Does the main Wikipedia/Wikimedia foundation really want to be located on French soil
and subject to French law with all international funds subject to judgements by French
courts? I don't think that's wise unless it can't be avoided.
2. Technically, isn't a caching proxy server a better idea? That way, those in France
can avoid the transatlantic round trip time increases but still edit the main
wikipedia/Wikimedia databases. (Mav, that's something your test didn't show,
unless you were doing it from a French proxy service)
3. Caching proxies seem like a better way to obtain legal isolation, since proxies and
caching are fairly widely accepted as being different from the sites they are caching. I
assume that the French foundation can be set up as a non-proft dedicated to increasing the
responsiveness of the Wikipedia when accessed from within France.
4. This is also a nice model for local caches around the world.