Your tutorial looks slick as hell .
I think it might be a little light on info though. Perhaps more text boxes that you can click "next" on or something to fill out details. Maybe go into the difference between moving a regular object by x/y and moving a physics object with Add or Set Force, or the difference between sprite rotation and physics torque, etc.
And I like the interactivity of it, perhaps you could include some more hands-on stuff like knocking balls around or stacking boxes. Things like objects of different masses colliding are easier to see when there's more than one object involved.
Really nice start though, I can't wait to see more