You can get the maps, but not the DBC files, I don't think.. I've not actually seen a working 2.1.0 yet..
I'd suggest copying over your entire WoW client to a new location and using that for your private server stuff. The only thing I have found that needs to be dealt with after running the wow.exe from the new location is, setting your "install path" back to the original before you launch the patcher (since the patcher/launcher might not verify your wow.exe or update it, but depend on the registry... if the wow.exe is what tweaks it, you'll patch the wrong directory!).. [HKEY_LOCAL_MACHINE\SOFTWARE\Blizzard Entertainment\World of Warcraft] is the registry location to make sure points at your proper install for playing on Blizzard servers..
hope that helps!