WOW! That sounds strange. Our school takes great pains to be sure each class within a grade level is pretty well balanced as far as ability and behaviour. I know nothing about long-term effects. Children with special needs get attention out of the classroom (gifted, learning support, etc..), but spend as much time in their class as possible.
What is done on a district level? This is something that I personally would be concerned about if it happened in our school.
Our new principal has decided, by herself, to separate the children in the classroom according to "learning abilities". In our school we have 5 classrooms in each grade. Two of the classrooms have been designated "high ability learners", two "average learners" and one "special needs" Does anyone have an opinion on how this affects the children in the end?