Yes, MPS and "language workbenches" in general are chasing something similar. Ideas like these are entirely in the details though, and so far I haven't found anything which does it for me. I could easily be missing it, in part because systems like MPS have a high up-front investment, and I have regretted such investments more often than not.
I don't think an IDE is the answer to the problem.
I think making Scala more correct and more modular is the answer.
Hygienic macros and syntactic extensions are more what I had in mind. Rust seems to be a solid contender here but it's much more of a systems language.
http://www.jetbrains.com/mps/
It sounds very much like what he is describing.