Smalltalk as a live environment blurs the boundaries between runtime and editing code. There's a video on ThingLab[1], a constraint solver, from 1978 where Alan Borning draws constraints graphically and then switches view to show the code that was generated. When he manipulates a constraint the runtime creates and compiles a new method based on the system that was graphically defined. That kind of thing would still be pretty awesome today (who generates JS at runtime for performance?).

Your comment reads a bit like "we cargo-culted the things we could see in the Smalltalk environment, but didn't understand the underlying philosophy or elegance of what had been made; what's left to learn?" (I know that's probably not what you meant, but I feel like there's a lot left to learn from Smalltalk and the tools that were built with it).

[1]: http://en.wikipedia.org/wiki/ThingLab (see link 4 for the video; it's really fun to watch).

Also check out: https://github.com/cdglabs/thinglab -- there's a link to a St-78 image with ThingLab. Also interesting to note proportional fonts, text selection (by Larry Tesler) and popup menus, all of which I thought came later...