Re: No... not really...
Years ago I predicted that AD would eventually just punt on domains, because the two models (tree vs. domains) are so incompatible. Remember each NT machine has essentially a local domain as well. I've seen "spaghetti networks" with impossibly baroque trust relationships. Yuk.
For file/print in a smallish environment (say, up to 500 nodes) Samba in DC mode is the ideal solution because it costs nothing. If you really need directories, use LDAP.
-drl