Mom2 in NYC they have integrated classes I don't know if that's the same as mainstream but my son 4.5yrs old is in one at a public school. They have 4 teachers, one a Special Ed teacher, and his therapies are incorporated into his day. There are approx 19 kids in his class and he does just fine. Mind you his problems thought to be autism turned out to be emotional. But he isn't lost at all as a matter of fact he is one of the star pupils in class and yes he's a little weird compared to the others but he's trying to relate, and has actually referred to some of the kids as his friends. It's been a wonderful experience so far and he feels very grown up because he eats the school food(UGH), rides a school bus, has various classes such as music, library, gym. He comes off the bus with a smile on his face everyday. I know it's frightening to let go a little and not be there to protect them always from the mean kids etc. but you'd be suprised how they manage, and learn to stand up for themselves.