Is it required to have a developer license on the target machine to be able to sideload metro apps? What if the user does not want/have a developer license (live id)? How do I get around it other than submitting the app to the store? Also, does the machine need to be joined to the domain to be able to sideloadthe app?
This Microsoft resource resumes it nicely: http://technet.microsoft.com/en-us/library/hh852635.aspx; in short unless you use Windows 8 Enterprise and are in a domain, the only way to sideloading is using a developer license.