How to admin a remote Windows Server with a command line interface?
PowerShell is what you're looking for. It is primarily targetted at system administration (although it's fanastic as a programmer's shell, too).
PowerShell v2 remoting is based on Windows Remote Management. See http://msdn.microsoft.com/en-us/library/aa384426(VS.85).aspx. It includes facilities for ecryption and authentication, as you'd expect.
PowerShell includes cmdlets that let you do a lot of everyday tasks. Microsoft server applications (IIS, Exchange, etc.) either have or are building PowerShell cmdlets to administer them. PowerShell's WMI support is excellent, giving you a lot of machine administration power. PowerShell can talk to .NET directly, which lets you go further than built-in facilities when needed. And writing C# for PowerShell to call works out cleanly, too.
You asked for a command line interface, but don't think that you're restricted to the ancient and crufty Windows Console subsystem. PowerShell v2 includes a new GUI interactive shell / script editor, with colorization and debugging. It's sweet.
You can also try http://sshwindows.sourceforge.net/
I don't have personal experience with it but it looks promising.
Did you consider Google? (looks like you edited your question. You now no longer ask if the example tasks can be achieved using PowerShell)
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