I also got some quick thoughts from Eric Hodel about his take on the JRuby announcement:
How do you think Sun's hiring of Charles Nutter and Thomas Enebo to work on Jruby will affect Ruby as a language?
Eric: I think the most likely change will be the addition of native threading, which is something that some people believe ruby has "needed" for a long time. I imagine it would also be possible to run ruby as an embedded language alongside Java.
I don't believe it would have much of an influence on the language or standard library, though.
The Ruby community?
Eric: Rails brought an explosion of interest in ruby and brought a bunch of fresh ideas. I don't think all of them were healthy ideas, but many of the language features were re-examined with fresh eyes and lots of neat stuff came out of it.
I imagine a bunch of Java developers joining the language will have a similar impact, but the community may have to educate them as well.
Your implementation of metaruby?
Eric: I'm not sure, not much of their code has utility to us, and our code could be useful to them if it was a few more years advanced at the current pace of development, especially on the Ruby2C side. I suspect we will continue to be separate for some time.