I created this little script in bash. It looks at eDirectory via LDAP interface and then walks through the file system home directories. It compares and then emails anyone that has home directories without a user. It is a little rough around the edges, but works well and is well documented. Do what you want with the script.
This was tested on SLES9 OES, and I am unsure whether it will work on NW6.5 sp3. I did not test on that platform.