I just finished watching the end of Bob Ippolito's talk on Erlang from C4.

At the end of the talk an audience member mentioned they were using Ruby and their senior guy didn't want to use Erlang so they wrote their own distributed queue thingy.

Bob said (not a perfect quote, watch the video to get it) "Ruby is great if you want to spend 15 to 20 times more on hardware than me".

Which makes me wonder... could it be Sun loves Ruby because it needs lots of their servers to scale?