also, I love the first line of the intro:
D3 is a powerful tool, but you know how that saying goes:
"With great power comes a conceptually clean library with a
learning curve like a wall".
I don't care if it's true or not, good writing :)
For these reasons, I hold that any piece of technical writing needs an introduction, no matter how familiar the intended audience is. It doesn't need to be long. But it does need to have its place (at the beginning).
HOWEVER! Either we all overlooked this: http://code.hazzens.com/d3tut/lesson_0.html (because this article links straight to lesson one) or the author has added an introduction in the mean time, because it does have an introduction :) So, all is good :)
(BTW I thought that D3 also brought a 3D framework to the canvas, but I see no mention of that anywhere--maybe I"m confused with the name and something else?)