The Enciclopedia libre at
http://enciclopedia.us.es/ is much larger
and more active than the Spanish Wikipedia at
http://es.wikipedia.com/
(in fact, it is by a large margin the biggest non-English free
encyclopedia and the third largest wiki in the world).
I think we should junk our Spanish Wikipedia, provide a link to their
site on our main page (they probably don't like to be called
Wikipedia, so we could simply say "non-English sister projects") and
have our interwiki links point to them rather then to the Spanish
Wikipedia.
And if we ask nicely, we may even get a link back to
wikipedia.com.
Axel
P.S. I would assume that over time, other international Wikpedias will
prefer to operate out of their own countries, to improve connection
speeds and gain more contol, and I don't see anything wrong with that.