Coming as I do from a country with two official languages (and by many
philosophies from a country of two official nations, not to mention
others as yet without official status), I take an interest in this
question of the Oscars and the Foreign Language Film category.  A film
from Anglophone Canada could not be entered, while French-language films
from Quebec could, and are.  (I believe both Le Declin de l'empire
americain and Jesus de Montreal, by Denys Arcand, reached the final
nominations.)  I believe I'm recalling correctly that Canada effectively
engaged in an atypical moment of anarchy a couple of years ago by
naming as the country's official entry into the Oscar sweepstakes a
very skilfully constructed film titled A Bullet in the Head (I can't
remember the filmmaker's name), produced in neither official language
of Canada -- produced, in fact, in no known language at all, but a
language fabricated only for the movie itself.  Unfortunately, the
Academy didn't respond to such constructive nihilism, and failed to
include the picture among the final five.
(By the way, Carol, I remember that Z was nominated and won in the
Foreign Language category, and may have been nominated as Best Picture
too -- I recall that it was quite an exceptional case that year --
and that it circulated in subtitled version in big cities and a dubbed
version (at the time a dubbing commended for high quality by comparision
with other English-language versions) in smaller markets across the US.)
The above is actually a digression, because what actually came to my
mind was whether a film such as El Mariachi, a US production produced
in a language other than English, might be eligible for nomination in
the Foreign Language category, or whether it could be nominated for
Best Picture.
Of course, given its relation to the standardized system of Hollywood
production, it would stand as much chance of winning as Beauty and the
Beast did.