Erlang is indeed impressive. But there is a big learning curve (at least for me!) and a whole new tool-set to support. It would be great if a Ruby/ZeroMQ based framework modelled on Erlang became widely adopted.
I'd expect an equivalent toolset on a different platform to have an equivalent learning curve if it existed at all.
http://blog.plataformatec.com.br/2011/03/why-rubyists-should...
Here's something I wrote about it 5 years ago:
IF you spend about 2 weeks working on erlang, it becomes really easy to use.
The learning curve is not nearly as steep as it appears-- its just that the syntax initially looks so alien that its quite scary.
I know the feeling, I went thru it, but it is well worth it.