I'd love it if they'd do ethnic food. However, I don't see it being 'marketable' for some reason. I mean, if almost all the popular 'ethnic' food restaurants are really Americanized, I can't see how having accurate recipes would catch on.
However, there is youtube.

Authentic recipes & techniques for lots of ethnic foods:
Middle Eastern food (she says Meditteranean, and yea, if you don't go any farther west than Greece, she's right):
http://www.youtube.com/user/dedemed
Japanese Food (with awesome Francis narrating):
http://www.youtube.com/user/cookingwithdog
Indonesian Food (with English translation)
http://www.youtube.com/user/IndonesianFoods
Korean Food (with a couple Kimchi versions too!)
http://www.youtube.com/user/Maangchi
Indian Food (vegetarian)
http://www.youtube.com/user/Manjulaskitchen
Indian Food (with Meat dishes)
http://www.youtube.com/user/ShowMeTheCurry
Authentic Mexican food, but you need to know Spanish. Or at least some spanish.
http://www.youtube.com/user/larecetadelaabuelita
Moroccan Food, with some western dishes:
http://www.youtube.com/user/cookingwithalia
Jewish Food (well, from the German/Western Europe tradition) made by a Grandma & her Grandson:
http://www.youtube.com/user/ChalutzProductions#p/u
Mexican food (some Americanized)
http://www.youtube.com/user/TRpicapica
And yes, I subscribe to all of them.

Now, if anyone can find me a Persian, Greek, Vietnamese and Spanish cooking show, I'd be super happy.

Ami