Despite that, I'm still not sold on the Traits concept. I'm not sure that sprinkling methods over a distributed set of Mixins would be fun to maintain, on a large scale. The Squeak implementation took advantage of the browser: you only ever see one method at a time in Squeak (smalltalk) code, anyway, and if the browser integrates with Traits, you could view and edit the methods as "part" of the class anyway. With Ruby, without a great IDE, you'd need to flick across files and use a bit of imagination to get a good "view" of your composed class - to even see what methods it's composed of. I believe that traits lose a good deal of their appeal without the Smalltalk browser, or a great Trait-aware IDE.
Interesting that he likes traits in Squeak better, due to the IDE support - one of my issues with traits - or method level namespaces - has been the whole dveloper presentation/understandability issue. It looks like I should grab Squeak and take a look, so that my preconceptions can be addressed with some actual data points :)