Over at Hypothetical Labs, the above question was asked: is there an erlang ‘groundswell’?
Personally, I think Erlang interest is growing. I just started a project using Erlang/Mnesia instead of MySQL as the backend, with Ruby as the UI. Erlang will continue to grow and carve out a niche. But it lacks the text processing and script-y-ness that makes Ruby such a joy to build web applications. I’d personally love to see a framework purely in Erlang that provides MVC, but also allows for construction of actual web pages in a ‘Ruby-lite’ language that gets parsed/compiled and executed in the Erlang VM.
Erlyweb is a good start, but it doesn’t go far enough.