I've got my dns server set up on the new DC for the Active Directory domain. All the clients are in an NT4 domain and are using a Bind DNS server on Linux. All clients think they are in the mydomain.com domain (netbios name MYDOMAINUK). The new domain is a proper mydomain.com with a netbios of MYDOMAIN (no UK at the end).

If I add the records to point to the new AD domain before the migration so that they can find the new domain, won't this cause problems for the existing domain because all the 2000 & XP clients will look to the new domain controller as the dc for the domain they're currently in...?

The other option is to point them to the new DNS server but this would have to be done manually on each workstation. I've found a way to migrate the clients remotely and don't want to have to go round just to change the IP settings... Is there another way?