I've definitely read that particular link and thought hard about how SICP should be written for a live coding environment. I don't think either the original SICP or Bret Victor will be the last word on this matter.

In Bret Victor's terms, the scheme used in SICP has very little "vocabulary" to learn to read. The first section (which I linked) uses only arithmetic functions and `if` to teach you, well, how to program. And the "show flow" examples emphasize mutation of variables through time, while scheme uses recursion in place of loops. I think something that shows the function calls explicitly would be good, or at least something that shows the flow of function call (like the DrRacket debugger).

At the risk of generalizing, Bret Victor deals with things like graphics, animations and simulations, while SICP treats programming like a branch of pure math, and it's not straightforward reconciling the two.

I'd love to talk more about this with you though!