Ruby as a language is a fence sitter. It's mainstream enough that it can be safely lumped in with PHP, Python, Java, C# et al. It's also offers features that make it a more powerful language than these *but* lacks crucial features that the truly expressive languages have like homoiconicity, tail call optimisation and higher order functions.
If you don't understand these abilities of Ruby, you will fail to see it's value proposition.
Ruby has an elegant object model, a strong tool set for object oriented programming and offers many of the abilities of more powerful languages by simply exposing an API to its AST.
This talk will touch on Ruby's object model and the meta programming API and techniques that utilize Ruby's more advanced features to pull ahead of Java and friends. It will also cover the weaknesses that prevent it from achieving the expressiveness of, say, a Clojure and the inherent risks of trying to replace good design with metaprogramming.
Hall: Hall 2 
Track: Development Tools and Languages