Ok – so I figured that someone was going to ask this question and therefore I tried it out myself tonight with the RTM version of Windows Server 2008.
Can I add a Windows Server 2008 server to an SBS 2003 / SBS 2003 R2 Network?
Yes you can. However you will find that the Connectcomputer wizard will not work. It fails with the error message as below
Basically – you need to do it manually. Run the wizard in the SBS Console to add a server to the domain and then do the rest manually. Set the servers IP manually, set the computer name manually and then add it to the domain.