I often have computers that are not in my workgroup and can access my DNS but I have to type in \\DNS323\ and than wait a bit for a list of shares to appear, once the list is generated accessing the DNS is just a fast as being on the same workgroup. This is of cause having open shares using v1.04 firmware but this shouldn't change anything if your using open shares.
I have also have work computers that are members of a domain work just the same.