Blake: In the 'Man! I want to check that out' category, I might put
either OpenQwaq or Open Cobalt.

Oh, and parsing expression grammar engines:
http://www.slideshare.net/esug/parser-inmypocket

Depending on your audience, you might feel the need to slip in a
mention of one or two dialects that are close relations of Smalltalk:
Frank, Newspeak, Objective-C or Ruby (modern doesn't necessarily mean
new, better or production ready, merely current.)

Hope that helps, David