In Ontario, Canada they completely got rid of special needs classes recently (so they aren't treated as second class or something), as well as gifted classes, and from two teachers and one child psychologist I talked to it's been a nightmare. Some classes will have 5+ disruptive students constantly yelling or fighting. And in the younger classes when a student has a "meltdown" they aren't allowed to send the kid to the principal, instead they clear the other kids out of the class to wander the halls, bring in the social worker lady (who is always on call), and wait until the problem kid calms down. They told me it was happening at least once a week in one classroom.

We're basically running social experiments on kids.