I've seen this done [on the Microsoft Learning Gateway demonstration VPC], but have no idea how to accomplish it myself and have a client who has a one server enviroment where they'd like to add a Sharepoint Portal.
Current Experiences:
If you try to install Sharepoint Portal Server on an AD root all of the options are greyed out and you can only install/operate WSS. If you add the Active Directory roll to a server after you've installed SPS the Central Administration generates a 'Service Unavailable' message.
Anyone have any thoughts how this could be done?