We are not on agreement about Microsoft’s intentions though. I think, they really wanted to create a GUI-less OS, but they failed. Server Core came into existence because of the Linux threat. There is no doubt about that. But the main difference is that Linux is a fully-functional server system without the GUI. Microsoft was only able to remove a part of the GUI, and thereby, they had to limit functionality significantly. So you could say that they failed in two disciplines.

Microsoft has to completely redesign Windows if they really want to compete with Linux in this field. Maybe MinWin will lead in this direction. We will see.

For example, this page on MSDN lists the DLLs that are included in Server Core:
http://msdn2.microsoft.com/en-us/library/ms723876.aspx
Note that gdi32.dll (Graphics support) is included as well as shell32.dll. OTOH comctl32.dll (the common controls) is not.

Over the years Windows has become a tangled web of services, with various services utilizing other services, often in unexpected ways. For example, code in ntdll.dll might invoke a function in shell32.dll. In Server Core Microsoft did their best to “clean house” – move services to better locations and cut out anything they could.

Creating a real GUI-less version of Windows is a much bigger project. This is what we may get eventually as MinWin:
http://en.wikipedia.org/wiki/Windows_7#MinWin