UPDATE: Windows Server 2010 RC has been released. This post may be valid but has not been tested.
For Windows Server-Core installation, Microsoft provided a system configuration tool that you can run from the command line. The tool is a scripted solution which provides commonly used server configurations/commands to ease administrator pain.
The additions in this version of Windows are:
10) Help improve the product with CEIP Participating
CEIP (also known as Microsoft Customer Experience Improvement Program), is to allow Windows to automatically send CEIP data to Microsoft for analysis and to improve their product in future releases. This is how Microsoft is able to analyse the commonly used commands in Windows Explorer, what do you click, etc.
11) Windows Activation
Previously administrators run slmgr.vbs activate Windows in Server-Core. Now sconfig provides the options to activate Windows with ease and no longer need to scout for command line options for common tasks that administrators use with slmgr.vbs.
12) Restore Graphical User Interface (GUI)
This is probably the most liked addition to Server-Core. Now you can convert a Server-Core installation to a GUI installation just by selecting this option.
So that's for the coverage on SCONFIG.CMD.