I don't know if this idea is too weird or too unimplementable, but brainstorm is brainstorm...
When I have to execute commands in a directory, I got used to navigate to it using Nautilus, right click on an empty space of the window, and select "open in terminal". When there is the need to open as root, I go one level up and click "open as root". I found these are great examples of combining GUI and command line functionality, getting the best of both.
Although it works, the procedure described above is kind of a workaround and involves many mouse clicks. Besides that, you end up with a lot of open windows with different focus (one nautilus as user, one nautilus as root, one or more terminals, etc). Not every user comes to realize the possibility of working this way, and most newcomers are delayed in the process of using terminal, because they find it not so user friendly. When reading forums, newcomers (as I was some months ago) are delayed to realize what to do to open a terminal, where the terminal icon is, etc.
THE SOLUTION / SUGGESTED IMPLEMENTATION
To create a way to open terminal like a panel inside nautilus, much like some text editors do: a panel below the main window, with a command prompt and some navigation facilities (insert filename upon click, cd to folder upon click, etc.).
It would be no open terminal for every nautilus window, but instead an icon at the status-bar or other lower window position, which would open a terminal at the selected directory, inside a panel.