Several people in the original LightTable thread mentioned that SmallTalk has many of these ideas. I confess that I know nothing about SmallTalk - can you please point me to a description specifically about SmallTalk IDEs and how they do all these things?
I'd suggest as a simple introduction, downloading a copy of "Pharo By Example" and working through everything in it.
Pharo isn't the prettiest of Smalltalk experiences, but
It will give you a glimpse into Smalltalk but really, it takes a good amount of time of use ( for me it was 9 months ) before I really got Smalltalk.
I'd also be completely happy to have an ongoing email conversation where I could answer any questions you have and fill you in on both the good and bad points of the current Smalltalk experience.