If you see Karl P sobbing during his State of the Nation address for IT consultants it’s because his favorite platform now blocks something he used to do. As first talked about on the SMBmanagedservices@yahoogroups.com listserve, Foundation no longer can support/do Remote Desktop Services -AND- be a domain controller at the same time.
Server 2012 RDS is designed under the basic premise that RDS servers will be joined to a domain, at least one RD Connection Broker will be present, and that RDSH servers will be managed as a collection using Server Manager (and/or powershell). Same is true for Virtual Desktops (VMs), they are designed to be managed as a collection.
Now, it is not impossible to have a RDSH server that is not joined to a domain and/or not a member of a collection. The thing to keep in mind is that most of the tools provided to make managing/configuring RDSH servers easier in 2012 will not work in a workgroup configuration. This includes most (if not all) of the new powershell commands and server manager. Most of the old powershell commands and GUI programs that would have allowed you to configure/manage a standalone RDSH server have been removed.
Exception to the above is for RD Licensing and RD Gateway. The GUI and powershell tools for those are still present in 2012.
To configure and manage a standalone RDSH server you may use a combination of local group policy (gpedit.msc), WMI commands, registry edits, and config file edits, as needed. For RD Licensing and RD Gateway you may use the graphical tools as in previous versions, or the old powershell commands (import-module RemoteDesktopServices).
For querying logged on users, logging off sessions, etc., you may use task manager or the query/logoff commands.
If your intention is to have a basic standalone RDSH server that allows users to log on and receive a full desktop, then it may be reasonable to configure using the methods I mention above. If your intention is to publish RemoteApps and otherwise attempt to use 2012 RDS to its fullest potential then I would not recommend you try to do it standalone.
If there is a specific setting on your RDSH server that you are unsure how to configure using GP, WMI, etc., please ask the question on this forum and someone will assist you.
My recommendation to you would be to set up your environment the preferred way as outlined in my first paragraph. You may still do this on a single server, but you will need to set up multiple server instances running under Hyper-V. For example, a single license of Server 2012 Standard will allow you to have Server 2012 installed on the physical machine with Hyper-V, and two VMs running Server 2012. In one VM you could have a domain controller, and in the other VM you could have RDS Role Services like RDCB, RDSH, RDWeb, RDG.
Please do not install RDCB on the same VM as a DC. This will not work. If you would like to install RD Licensing on your DC that is okay.
Having a standalone Server 2012 RDSH will require more work and the number of people that will understand how to assist you if you have problems is relatively small. If your needs are basic then the extra work/limitations may not be a big deal.
Please let me know if you have any questions.