I've had some very positive feedback about the Extract Mixin entry awhile ago. Pat Eyler wrote a blog entry about it, and Chris Hedgate also found it useful.
In his blog, Pat asks the question whether Ruby will spawn a set of new patterns, or change the way we look at existing patterns. I firmly believe it will. It's not just Ruby though. Languages have different features, and they also emphasize different things, and have different cultures built around them.
There is a lot to learn from immersing oneself in different languages and cultures. What you learn in one place, can often be used in another. I was a Perl programmer before I began working with Java.
Perl taught me a lot about how to just get things done and that there may be more than one valid approach to solving a problem. This, I hope, fostered a spirit of openness. (Though it is really for others to say how that turned out.) It also gave me a different perspective on object oriented programming and design patterns than I got from Java. Perl also taught me the importance of unit testing, something I have brought with me ever since.
On the less technical side, the Perl community, and CPAN taught me a lot about the value of working together, and that even if you contribute only a little, you will get it back a thousand times. (Quite literally in the case of CPAN.)
One thing Java taught me is the value of a good IDE. I rarely leave home without Eclipse in my backpack (tucked away on the hard drive of my laptop, of course). Java also taught me some things about how to coordinate team efforts, and (by not having it) why it is a really good idea to have a standardized way to install libraries. I also learned not to use frameworks that have tightly coupled frameworks (anything with EJB in it), and to appreciate the power of simplicity (Spring and friends).
Java also taught me a lot about the importance of refactoring and many other development practises. Beyond that, the Java projects I worked in rekindled my interest in development methodology and management.
And now, it is Ruby. Ruby is a very nice language to work with. It allows you to cut to the chase and focus on solving a problem. The Ruby community is much like the language: friendly, open, and lazy (in the Perl sense, i.e. believing strongly in getting the maximum of value with the minimum of effort).
I like it. The Ruby community is a place where I can grow.