meejah, What if instead of user-stories, the UI was a story ...
... can't stop thinking about a pixel-art themed, "point-and-click adventure" style UI (think "Sierra Online" but fast) that teaches you about the protocol slowly, as you go ... adding more options / features as you explore
Maybe not completely thought through yet, but would you use a "serious" application that had a "fun" interface (assuming it was still fast / small enough to get stuff done)?