Since before the days of DOS the command line has been the down and dirty way to issue commands, start programs and list files. But how has the command line changed in the these years? Fundamentally it's all the same, you list files, change directories and pipe commands.
Some command lines in UNIX have options to color code certain aspects of the output... Oooooo. The addition of command line auto-complete has also been a huge time saver. I take minor credit for getting this turned on for the release of XP, it was in Win2K but it wasn't on by default. Ahhhhh. Over twenty years of computing and the metaphore hasn't changed a bit.
Image a new command line that combines the strengths of a command line tool with the interaction of a graphical user interface. You type Dir or ls and get back a listing of icons. You select a couple files with the mouse and press Ctrl+X to cut the files into your clipboard. You double click a folder and it issues the CD (change directory) command moving you into the folder. You press Ctrl+V to paste your files into this folder and this executes the Move command with the appropriate files.
As you continue to work your previous command, folders and files continue to scroll up in the same way that today's command line works. Now type "dir /details" and get back a listing of files complete with column headers. Now sort your files by size, filename or changed date.
The concept is not limited to files. Other command line tools should be able to interact graphically within the command line space. For example type the unix command "top" and see a live graphical chart showing you the processes taking up the most CPU usage. Type the dos command "tree" and get a functional tree view control of your current directory.