I don't see the point in this as a serious production language. As a project to just have fun, of course it is a cool idea.<p>Lisp systems moved to generic functions for a reason - Lisp dialects for some time used a Smalltalk-based message sending model, but it just isn't as flexible.<p>But if the desire is to get Ruby semantics with Lisp syntax, I think the much more reasonable approach is to run a Rubyesque Lisp on Rubinius (which the lead devs have already talked of doing). At least by doing that you get the advantage of piggybacking on an advancing VM and a language that already has libraries.<p>Establishing a new language is hard.
Disclaimer: I haven't tried Nu yet, just read the FAQs.
Nu isn't about Ruby semantics, it's about Cocoa and Objective-C semantics. It's a Lispy/scripting way of interacting with the Mac OS programming paradigm. The author is also the author of the RubyObjc bridge, and Nu was a result of his frustrations with the "impedance mismatch" between Ruby objects and code and Objective C.
Slightly off topic, but there was an interesting example on one of the documentation pages:<p><p><pre><code> % (set laws "Asimov defined #{(+ 1 1 1)} laws of Robotics")
% (puts laws)
Asimov defined 3 laws of Robotics
</code></pre>
Are there any other standard ways to embed s-expressions in strings?