"The first thing you need to understand is that the purpose of refinements in Ruby 2.0 is to make monkey-patching safer. Specifically, the goal is to make it possible to extend core classes, but to limit the effect of those extensions to a particular area of code."
I went to RubyConf and heard a detailed presentation on a new possible feature of possible Ruby 2.0 called ‘Refinements’. I have to admit that I didn’t fully grasp how the feature really would be used. Here’s a nice and quite techical article about it: Ruby 2.0 Refinements in Practice from Katz Got Your Tongue?: