Gleaning: Iron Ruby is a ways off. I got somewhat impatient and have been using IronPython in the meantime, but more on that later. That's not a small decision for me because I am of the Norvig perspective on learning a new language - it takes the length of time needed to think in terms of the idioms of that language, as opposed to just writing your code with different syntax and keywords (ala writing C# in Ruby).
Gleaning: Ruby is a powerful language for creating domain specific languages. That meme has been floating in my head for a while - listened to a good Software Engineering Radio podcast on the topic sometime back.
Gleaning: JLam talks a bit about how the learning curve for new languages these days revolves around the frameworks for languages - I think the idea of Ruby combined with .NET is that the .NET libraries will fill a gap that Ruby has always missed in library support. Dangerous or brilliant? In other words, I'm sure the open source crowd (is/will be) up in arms because this will, in their minds, dilute the community effort behind a language. Brilliant because the Mort you know (who is probably your boss) will have a better level of confidence about using it.