Scratch

I think there should be a new feature on Scratch 2.0 (or if it's too late to suggest for that, any future version). It should be a tracing feature for Backgrounds or Sprites, to make it easier for animators to...well, animate.

Basically, you should be able to click copy background and then click a button that says 'trace background' which should enable you to draw 'on top of' your last background but without editing your original background, like slipping a sheet of tracing paper between the two backgounds. So for example you could create frames for an animation much easier that way, or sprite's movements for, say, a game or something.

Suggesting an idea to the community,
JinnOfTheGale