I was wondering the same thing about using the model itself rather than a language. I asked this on StackOverflow and received some interesting feedback http://stackoverflow.com/questions/10323393/is-the-actor-mod...

The short version: apparently you can do this in other languages, but erlang (and possibly other languages) have this concurrency baked-in much better.

p.s. also worth mentioning RabbitMQ on the list of famous erlang projects