Bret has certainly been an inspiration to lots of us who work in this field, but I still don't think this is an implementation of his vision. To truly implement his vision, someone would need to design a new programming language and environment.
My motivation has been to ease the learning path for an existing popular language (Python).
I have been thinking of such a language for several years. Now that life programming environments are getting traction, I might be able to bootstrap the process and program my ideated language on top of one of them.
See this 2003 PhD thesis at MIT for two examples of existing languages designed to take full advantage of live programming environments. (Flogo I -graphical- and Flogo II -textual):
http://llk.media.mit.edu/papers/ch-phd.pdf
Particularly interesting is Flogo II capability to mix the imperative and functional-reactive programming paradigms in the same code block, as parallel runtime processes; I hadn't seen that before.
Christopher Hancock's thesis is pretty good; flogo II plays around with this feature called "live text" where it embeds code exucution visualizations directly in the text of the code. I still haven't seen anyone pull that off again.
To clarify: I didn't mean that it was whole his vision, nor did I thought you was inspired by his recent text (someone mentioned in the other thread that your tool is around for months). But this is a living example of one of the ideas he discussed in his last essay (even if this example is independent of and older than the essay itself).
My motivation has been to ease the learning path for an existing popular language (Python).