I really don't want too much to be made out of it, since Slate (http://slate.tunes.org) is essentially in a coccoon metaphorphosizing (being bootstrapped), that I can't give you a system that does all of this Right Now.
However, I must mention that you can achieve nested lexical overrides without invoking dynamic scoping through the use of macros, i.e. compile-time code expansions, which Slate handles in a nicely-compatible way with existing Smalltalk.
Slate also has the property that methods do not return "self" implicitly, as mentioned earlier, and that the global namespace is rather heavily structurable. It also allows for a fairly uniform package structure which is amenable to capability analysis, but this has not been fully-developed yet, only outlined.
I have followed the E and Squeak-E dicussions with great interest, and will certainly be incorporating ideas as I can into Slate.
Anyway, that's my reluctant plug-of-the-month.
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