The law varies depending upon whether it is an in-state or out-of-state move.
In state, the receiving SD must use the IEP until they develop their own. That means, since IEPs are ususally developed in the spring, they will "inherit" the IEP for 2007-08. If it is an out-of-state move, then all bets are off. The SD must provide FAPE, but they get more latitude to do so.
I would contact the receiving SD and try to get a feel for their intentions. A telephone call is not what I ususally suggest (a big DUH to regular readers of this Forum) but what you do next depends upon what their ideas are.
It woud be nice if all SDs folllowed the law but they don't. So although what I have written above is true, that does not mean they will do it. For example, the receiving SD could say, "we don't "DO" outplacements," which is not legal but it certainly has happened to parents and kids. After you find out what they have in mind (which may be nothing) then ask BY CERTIFIED MAIL for an IEP meeting. You need to have all the documentation that resulted in your difficult child's outplacement. You probably do not want to have them "give him a chance" in regular class. That, I would predict, would not end well.
Moves are diffiuclt for all kids....more so for most difficult children. The goal would be to get difficult child to trasnition with the least regression possible in learning and behavior. If you can get the SD on board with this goal, that would be a positive step.