Being a North American grade 8 student myself, I know what is going on. Most black kids are doing poorly in their schools because they don't understand the teachers and the teachers do not understand them. Almost all teachers in here are white and it's just not easy for them to get along with black students.
For one, black students tend to make fun of the teachers a lot, and so the hatred forms between them. If the students had a teacher who was "equal" to them, they would understand and respect the teacher better. Attitude is BIG here, because the white teachers give the blacks attitude and the black students give the white teachers attitude.
Secondly, here in north american schools, white teachers are not considered that much "fun" to blacks. At the same time, a black teacher who is equally (if not more) strict gains more respect from the black students, because they are considered "cool". Therefore, the black students listen to these teachers with more respect.
I feel that if you look at it academically, this is a good idea. I am 200% sure that black students will do better in school if these schools come up. But, if this is going to start too many differences between whites and blacks again, maybe it won't be a good idea. I guess we have to choose between the academic future or the racial future of the black students.