Hi there!
For some things I use the Command line because it's a lot faster than the gui.
I have a website, and most of the times I use the command line FTP to upload the files instead of Windows Explorer because it ends up being faster...
I also like the option on the command line to filter files. Yes, the old dir command... =)
If I want to see files containing "home" on their name, I just do dir *home*... You can't do that with Windows Explorer (though you can on the Open dialog).
I'll just wait and see what the new Longhorn command line will be like! =)