So you have implemented Active Directory 2008 .. I hope you did some investigation in backup/restore and offcourse you must update your disaster recovery documentation now.. to help you on your way Microsoft has released a new whitepaper on Forest Recovery for Windows 2008… read before and while fixing your AD.. (preferably before )

http://www.microsoft.com/downloads/details.aspx?familyid=326C8A7A-DCAD-4333-9050-A6303FF3155C&displaylang=en