NodeJS, been there done that. Even with generators it makes doing task synchronously a royal pain(have you ever tried to write sql update code with transactions?). Until something comes a long to replace Ruby(https://github.com/mirah/mirah looks promising), I'll still use it. Ruby is a great scripting language, and it has one of the best(if not the best), web frameworks out there.

I definitely think MRI will die, and Ruby will live on in the JVM. I've been really impressed with JRuby and the advances they have made on that project.

Plus you also have projects like RubyMotion and the promising Opal(Ruby to JS).