realized

So i have an existing network running off a single server running windows 2003 SBS. I am about to add a file server that originally was going to run Linux.. However.... i was wondering if i set up windows 2008 if i could add it as another domain controller? I just saw this: Adding a Server Running Windows Server 2008 to a Windows Small Business Server 2003 Network which seams to say i can... the goal of the 2nd server was to only be a file server... however, if i could use it as sort of a fault tolerance for the services running on the SBS machine (dns,wins, print server, sql, login server etc) then that would be cool as well. Thank you!