Possible way to migrate a small Active Directory domain?

Solution 1:

I will gve you the same answer I gave to a very similar situation this morning:

In the short term, clearly a trust is the way to go. In the long term, you will probably do it using the Active Directory Migration Tool and the Password Export Server.

http://www.microsoft.com/downloads/en/details.aspx?FamilyID=20c0db45-db16-4d10-99f2-539b7277ccdb http://www.microsoft.com/downloads/en/details.aspx?familyid=F0D03C3C-4757-40FD-8306-68079BA9C773&displaylang=en

I suggest that you read this document Microsoft on how to use the ADMT and restructuring domains.

http://www.microsoft.com/downloads/en/details.aspx?FamilyID=6D710919-1BA5-41CA-B2F3-C11BCB4857AF

Solution 2:

Is it a must that you must change the domain?

because you can affectively just add new 2008 servers and promote them to DC's instead. Once replication has happened you can move all the FSMO roles acorss to the 2008 servers then decommision your old servers. You now have the same domain but with new hardware. You can then upgrade the domain to be 2008 compliant once old servers are gone.

Basically this achieve all your goals above except the domain name will be the same.