With a basic desktop install + porthole, a user doesn't even need the command line any more... after the initial setup, that is, which the local geek (that's us!) can handle.
Not even that. The latest LiveCD has a graphical installer.
You still need to know what you're doing (which is what the handbook is for), since the installer is just a front end to everything you'd normally do, but it helps smoothen the process and keeps you away from the command line (which is still available should you so choose).As for Porthole, I found it nice, but quite buggy last I tried it (it liked to crash a lot). You couldn't review the USE flags for packages pulled in as dependancies, as you can with 'emerge -av package', and the status window used a horrible non-monospace font with a white background (you'd get more readable output with a dark background and a monospace font).
For KDE users, Kuroo is another Portage front-end, which is currently being put through its paces by the kde-usability team. It looks pretty snazzy, but the current version I have doesn't work.
