In previous versions you could identify CORE installations from the OperatingSystemSKU attribute in the Win32_OperatingSystem class. Reference:
http://technet.microsoft.com/en-us/library/dd184083.aspx
This is no longer possible, the attribute does not differ. Is there any WQL statement to distinguish "Full Server", "Minimal Server Interface" and "Core"?
Right now I helped myself by quering "c:\windows\explorer.exe", whicht does not exist in Core. But this is not as useful as a WMI/WQL query.
Thorsten