True, but how you connect depends on your security. If you don't supply a user name and password, and if that user is not part of the PUBLISHER or ADMINISTER roles in server, then you won't be able to manage or pupblish services from your desktop. We use gis tier and token security as our AD policies are too restrictive to effectively manager services. As such, I add users, passwords andd and assign them to roles via scripting. But, we still use an AD account for our arcgisserver account as we have a distributed cluster environement, with single-sign on or federation not an issue for us.
David