Received a picture book in the mail today: SPEAK TO ME (AND I WILL LISTEN BETWEEN THE LINES) by Karen English, illustrated by Amy June Bates (FSG, 2004). I don't know Karen, but her debut novel, FRANCIE, was wonderful and a Coretta Scott King Honor Book. No information on Amy, except that it says on the flap that she's from Ann Arbor, which is where I went to law school. The book features alternating point of view poems in the voices of young African American characters.
FSG is one of the few national publishers still doing multicultural literary trade picture books. Clarion (particularly with Asian American) and Charlesbridge are still hanging in there, too. There's another house or two, I'm sure...but their names are just on the edge of my mental facilities. Boyds Mills, that's one. Small lists, but the quality and diversity are there.
I realize multicultural publishing is fraught with challenges. No way around it, though. African American children's and YA books are definitely the strongest of the historically underrepresented groups, though Hispanic/Latino and Asian (by which I mean Chinese and Korean American) are coming up strong. Books featuring Jewish characters and gay/lesbian characters are on the rise, but the topics are still somewhat limited.
As for the rest, the numbers are still pretty awful across the board. Native, Southeast Asian, Arab and so forth, we should perhaps look to the African American children's book community as a model.
Maybe start by checking out: BLACK BOOKS GALORE! by Donna Rand, Toni Trent Parker, and Sheila Foster (John Wiley & Sons, 1998). Features descriptions of 500 books, award listings, tips for encouraging young readers, and highlight articles on a sampling of African American authors and illustrators.